Monday, 7 January 2013

Ducati Desmoquattro Superbike FAQ

I wrote the Ducati Desmoquattro Superbike FAQ a few years ago based on my own research when I was looking for my personal 916. I've since updated it with corrected info and personal experience with my intemperate Italian bitch. If you want to buy a 748-916-996, this is where you should start.

What’s good about them?

Well, many things. Most people tend to agree that the 916 series is a ground breaking model and will remain a classic motorbike for years to come. This ensures decent resale and means you’ll always know you bought a motorbike with genuine heritage and prestige. They are beautiful machines, inside and out, from the small details up to the bike au complet. The Italians are particularly good at making the machine as a whole seem like an intricate piece of art, with individual parts being beautiful on their own merit as well as bolted together. Beyond the good looks, these bikes are great to ride too. Handling is very manageable and confidence inspiring, not to mention very stable. These bikes are very responsive to suspension setup and mild performance tuning, turning a great bike into a fantastic one. And few will argue against the cachet and head turning potential of these machines.

What’s bad about them?

Many things. They cannot be neglected or abused – they require frequent maintenance and careful servicing, otherwise they will suffer serious mechanical failures. They need to be used regularly or they will suffer a whole other set of problems. The electrical system is inadequate on early models, without exception. They are dogs to ride at low speeds, they are uncomfortable, and they are utterly uncompromising machines. They were designed as race bikes first and street bikes second – remember that and it won’t seem so bad when you are stalling and cooking yourself in traffic.

As I will explain, there are many areas that need attention, and many things that can go wrong. But if you are a patient tinkerer with decent mechanical ability, or someone with a fat wallet and a helpful dealership, then you can keep them running well forever. And most of the faults are relatively straightforward and easy to rectify given adequate patience and a careful hand.



What goes wrong?

Electrical – the pre-1999 charging systems are completely inadequate. The 916 uses a piddling 350 watt alternator that has a hard time keeping its 16 AMP battery charged without regular hook ups to a trickle charger. You need to ride for at least 15-20 minutes with varied revs to recharge the battery from a cold start or a few days of sitting.

The early style alternator uses a stator hub bolted to the end of the crankshaft on the left side – the nut holding the hub on has a tendency to loosen and can cause engine seizing, if not serious crankshaft and alternator damage, so it needs to be verified regularly (upgraded locking nuts are recommended, especially on 996s).

The regulators on early models are prone to failing and should have been replaced with an upgraded, metal backed item – but even these can overheat next to the horizontal exhaust pipe, unless they are relocated into a cooler spot with better airflow, or better yet replaced with a solid state MOSFET unit that runs considerably cooler (and is cheaper than a replacement regulator from Ducati).

The wiring has a tendency to burn out quite easily if the system is overloaded. The system is not really weatherproof either – none of the connectors are greased at the factory and key components are exposed to corrosion. It’s a good idea to go over the entire system with dielectric grease as soon as you get a hold of it. It’s not uncommon for a bike to refuse to start after rain riding or washing, simply because water gets into the connectors and corrodes them. 

Things that break – Certain things on the Superbikes are fragile, and commonly crack or break. Some you need to worry about, some you don’t… some are potentially catastrophic.

1. The coolant reservoir/expansion tank is located inside the frame ahead of the airbox and under the fuel tank; because of its complex shape and awkward position, it tends to crack and leak. Keep an eye out for leaks and fix it ASAP. Cracking can be prevented by NOT overfilling the reservoir with coolant (keep it at the recommended levels!) and by thinning down the rubber grommet that holds it in place slightly to account for heat expansion.

2. The plastic airbox on early models (pre-1999-ish) is a bit thin and commonly cracks along the creases of the plastic and around the mounting holes. This isn’t really anything to get upset about, just seal the crack with black silicon. You can always put on a later airbox or if you have the money get a carbon fibre replacement.

3. The triple trees and clip-ons can crack – this is a serious problem and if it pops up it needs to be fixed immediately – you don’t want a fork to fall off or a clip on to snap while you are riding. This is a rare but serious condition. Check the triples and clip ons at each service and always respect the torque specs for the pinch bolts.

4. The rear wheel spindle was recalled for the potential to develop hairline fractures – dealers were supplied with an ultrasound machine to check for invisible cracks. Make sure this has been done.

5. The oil pressure switch (or “sender unit”, located ahead of the clutch cover) commonly fails. I’m on my third. It will usually start setting off the oil light intermittently, and oil will seep up through the switch. Obviously if the oil light starts coming on, check the oil pressure right away – if it is within specs, then your pressure switch is to blame. Order a current spec replacement switch “kit” from Ducati, about 35$ including an upgraded waterproof connector.

6. The stock clutch slave cylinder on early bikes is very likely to blow its seal and dump the hydraulic fluid, leaving you without any clutch control. If you are masochistic, keep a few spare seals to replace them when it happens. If you are smart, buy an Evoluzione double-seal piston or an aftermarket slave cylinder to fix or replace the stocker. You can also put the later (2001 plus) sealed slave cylinder on, but you need to add a 10mm spacer inside or get a longer 2001+ clutch pushrod to match. I did this on my bike, using a 10mm length of M8 bolt sawed to length and dropped into the pushrod to take up the space.

7. The stock sidestand is a spindly aluminium item, and is very fragile compared to a cast steel item. So don’t put any undue stress on it – this means ABSOLUTELY NO levering the bike onto the sidestand to clean the chain or spin the bike around, and always set the bike onto the stand gently. You do not want one to break unexpectedly, especially while levering the weight of the bike on it. I’ve broken one and it scared the almighty bejeezus out of me, fortunately it didn’t topple over when it happened.
 
8. Generally, Ducati has a fondness for aluminium bolts. These are nice and light, but they are also prone to stripping and breaking very easily. So always be gentle and follow the recommended torque specs whenever you are removing or installing anything.

Things that fall off – Here again, there are a number of items that need to be watched and loctite-ed to makes sure they don’t fall off on the go.

1. The fuel tank front mounting bolts have been known to rattle loose and fall out – this doesn’t sound so bad, until you realize the bolts site directly above the front cylinder intake. Dropping an 8mm bolt into a running motor’s intake in a quick way to have a spectacular blow up. There are two bolts securing the front tank bracket to the bottom of the fuel cell, pull off the tank and secure these with loctite ASAP.

2. The sidestand, when the suicide spring is bypassed, has a tendency to back out its mounting bolt. This is because the snap-up spring is connected to the nut that secures the bolt in place – to bypass the spring you need to get a shortened bolt and ditch the securing nut. This means the bolt is only held in place with a tiny amount of thread. You will notice it when it starts to back out, the bike will begin to lean over further than usual on the stand. My recommendation is to get the bolt and spring off a late-model bike (they are all pretty much the same). Current models have a sturdy nut and bolt assembly with a special spring plate in the back that bypasses the suicide-stand. Slap that on with some thread lock and she ain’t going nowhere.
 
3. The oil pressure switch won’t fall off (thankfully) but the wiring to it is pretty floppy and gets tangled in the wiring harness near the battery, so whenever the wiring is disturbed it has a tendency to disconnect the pressure switch. If you notice the light is off when the ignition is on but the motor is off, then the wire probably came loose and needs to be reconnected.

4. The front sprocket (“countershaft sprocket” in Ducati speak) is a unique fully-floating item. This means is loosely attached to the output shaft with a small brass plate secured with two 8mm bolts. It’s normal to have a significant amount of sideways free play in the front sprocket but you have to check the tightness of the securing bolts on a regular basis, and loctite them regularly as well. Also replace the retaining plate every few thousand miles, it wears out quickly and should be renewed AT LEAST whenever you replace the front sprocket. The retainer plate is quite cheap so I replace mine every 6-10k miles.

Fueling – The fuel system is quite prone to clogging the filter and splitting the fuel lines inside the fuel tank. Replace the fuel filter regularly and keep an eye on the line for splits – when they happen, replace the all the internal lines immediately with good quality items, I recommend UAP/NAPA submersible-rated high-pressure fuel injection line. Most models use plastic quick-disconnects to connect the tank to the fuel lines – these should be replaced with metal items (available from Triumph for 955i models, or from OMEGA lab supplies) because you WILL break at least one in your period of ownership. Make sure the replacement connectors have Viton rubber seals. Viton o-rings are used to seal the fuel tank and the quick disconnects, and woe to the person who doesn’t keep spares for either of them. You can get generic Viton rings from industrial suppliers for pennies apiece, order a bunch in bulk and never worry about running to the dealer to pay a buck for a 2 cent o-ring.

Rockers – On post-1996 models, the rocker arms of the valve system are prone to flaking their chrome. The rockers are coated in chrome where they contact with the camshaft lobes, and it’s here that the chrome will wear, pit, and eventually flake off, leading to camshaft damage and flakes clogging the oil system. The only solution is to buy aftermarket hard-chromed items from MBP or Megacycle to replace flaking rockers – buying OEM rockers will not fix the problem and they WILL simply flake again, no matter what the dealer tells you. To check for the rocker arm problem, pull out the handy oil strainer on the right side of the motor above the drain plug and look for chrome flakes. If there are flakes, you need to open the heads and take out the cams to check the rocker surfaces to know which ones need replacing. If you don’t find flakes, you can probably rest easy, but the cams should be pulled and the rocker faces verified at every valve adjustment regardless.

Galley plug – on any pre-2001 Ducati, there is a possibility of the crankshaft oil-galley (sometimes called “oil gallery”) plug to back out and start grinding on the inside of the crankcase (actually the bearing race of the main bearing on the left hand side). Eventually the plug will fall out and you will lose lubrication to the big-end bearings – meaning big engine failure. Check the oil strainer for slivers of aluminium from the plug rubbing the crankcase (they will look like fingernail clippings, long and thin, whereas chrome flakes are usually small and flat). To fix it, you need to split the cases, pull out the aluminium plug and replace it with a post-2001 steel item secured with high strength threadlock and some heavy staking. It’s a cheap part that can cause big problems if it starts falling out, and along with the rockers is one of the main things to watch out for, especially on higher-mileage examples.

Belts – Camshafts are driven by an automotive style Kevlar-reinforced rubber timing belt, and these MUST be replaced every 2 years or 12 000 miles. If not, the belts can snap and head and piston damage will result. Any bike that has been sitting for long periods of time or has really low mileage is in danger too – the belts will snap if neglected over several years. Early belts were not Kevlar reinforced and are more prone to snapping – these are identifiable by their white lettering, as opposed to red on the Kevlar items. OEM items from the dealership run around 100$ apiece, but you can buy identical Bucci  or Exactfit belts from third party suppliers for around 45$ each.

Crankcase breather – Ducatis have a fair bit of crankcase pressure. On race bikes, double breathers (the famous “pompone” bikes) and large volume undertail breather boxes were used for maximum power. On the street bikes, the breather is still pretty large by conventional standards. Unfortunately the stock breather isn’t the best design and is prone to getting overwhelmed with oil and misting oil over the rear cylinder. So a fine mist of greasy buildup around the breather is normal. If it bugs you, you can always get an improved aftermarket breather and reed valve. Also make sure you don’t overfill the oil.

Wheelies – Ok, wheelies and stoppies are bad for any bike. Tipping the sump backwards or forwards will shift the oil away from the sump pickup. On Ducati superbikes you have an added problem – the above-mentioned crankcase breather. Oil will shoot up the breather when you pop a wheelie, and has the potential to either spit oil into your airbox (best case scenario) or spray it over your rear wheel (very bad, especially when you are in the middle of a wheelie).

Airbox seal – Ducati superbikes use a unique airbox setup – the top half of the airbox is the bottom of the fuel tank, the bottom half is a conventional looking box with an open top bolted into the frame, with a rubber seal between the two. Lift up the tank and you are looking straight into the throttle bodies. Air is fed into the system through ram-air ducts along the sides of the cockpit; instead of putting the filter into the airbox in the conventional spot, there are two filters, one in each air runner. This allows maximum airbox volume, the best airbox resonance, and good intake pressurization. Unfortunately, the airbox seal between the ‘box and the tank isn’t great, and dust can seep in. The best thing to do is coat the airbox and the runners with a layer of chain lube, install a better seal, and use oil-permeated foam filters. Some companies sell foam filters that slip over the air intake trumpets – these will prevent dust from getting into the intakes, but it also takes up airbox volume, allows junk to get into the airbox itself, and destroys the crucial resonance effect. I’ve used them and I don’t recommend them. The fact stock filters cost a fraction of the cost of ineffective aftermarket items, and work best in most situations, is reason enough to leave them alone. 

Bearings – Italians mechanics seem to have an aversion to grease so check the condition of the steering and wheel bearings, and be sure to load them with fresh grease whenever you can (where applicable, sealed bearings are sealed for a reason and can’t be repacked).

Drops – Ducatis are fragile machines, and a simple drop in the garage will mean a big repair bill. If dropped on the right side, the battery can crack and leak acid on expensive engine and frame parts, and the external dry clutch is easily damaged in lowsides. Fairings are expensive and easy to crack, as are the mirrors and mounting stems. All of this is not aided by a spindly aluminium sidestand that is prone to breaking and/or backing out its mounting bolts. This is assuming the dreaded “suicidestand” has been bypassed - the original stands were spring loaded to snap up as soon as the weight was taken off them, and rigged so that the ignition was cut when the stand was down. This means the bike would easily fall if bumped, and could not be idled to warm up without sitting on it. Get an aftermarket stand bolt and a bypass kit if it hasn’t been done already.

Oil – Ducati recommends 10w/40 viscosity oil in the desmoquattro motor. Most people agree 15w/50 or 20w/50 is a much safer bet, and full synthetic is highly recommended. This is better for the bottom end bearings and for the rocker arms, which are prone to oil starvation due to the nature of the oiling system. Always let the motor idle until the temperature gauge hits 140 degrees before touching the throttle, otherwise you may exacerbate the rocker arm flaking issue. Your engine will thank you in the long run if you take the time to change the oil and filters regularly - with top quality items - and always warm up before riding.

What’s that noise?

If Ducatis are unique in nothing else, it’s in the noises they make. Some things can be disconcerting to newbies to the brand, so here’s a rundown of what to expect:

Dry Clutch – For those in the know, a Ducati dry clutch is a trick piece of race engineering for the road. To those who don’t know, it’s a bit scary. The clutch is located on the outside of the crankcase, and as the name suggests, it’s a dry multiplate unit – it’s the same as in any sportbike, except it doesn’t sit inside the engine bathed in oil. There are many benefits (and as many drawbacks) to this system, which I won’t bother describing here; needless to say, it’s a unique system, and has the distinction of making one hell of a racket. The noise is due to the clutch friction plate tabs rattling in the slots of the basket as the clutch spins around. I’ve heard it described as 1970s Buick with a broken conrod, or as the sound of a shot crank bearing, or a pair of skeletons having sex in a trashcan. Whatever it sounds like, it’s loud, it’s different, and it’s nothing to worry about. It will clatter and clack (tackatackatacka) when you leave it idling in neutral, and will jingle and boom (kerchinkakerchinkakerchinka) when you pull the clutch lever in. It will also clatter loudly if you lug the motor below 4000 rpm; driveline lash is a problem with the dry clutch, big power pulses, and a floating front sprocket. If you run an open cover you will also hear it when you shift or when under moderate load. If it really bugs you, you can always put a sound-deadened solid cover (available after 1998, you can tell by the padding inside the cover) or buy an aftermarket fitted clutch pack that won’t rattle back and forth in the basket.

Intake – Another source of glorious racket, the intake roar of an early Superbike is truly awesome. Pre-996 models (916-748s) had unrestricted intake runners that generate a phenomenal roar from around 4500 rpm up. This is the airbox resonance effect, sometimes called Hermholz resonance; it’s the sound of the air alternately pounding into and getting pushed out of the airbox by the ram-air and intake effects. It’s a good noise, it means the intake is working properly. 996 and later models had rubber venturi blocks inserted into the intake runners after the air filters to dampen the noise – if you want the full noise effect open the runners and pull the restrictors out. Alternately if you don’t like the noise buy some restrictors and put them in. 

Cams – Here we are talking about a lack of noise rather than an abundance of it. Because Ducatis use automotive-style timing belts to drive the cams (look at a Ferrari V8 and compare it to a desmoquattro with the belt covers removed) there is almost no camtrain noise, especially compared to the whirring and whining of chain or gear driven cams on most bikes. You might notice a slight twittering noise on overrun if anything – those are the desmo valves at work. The belt drive makes a soft whirring noise as well. Loud valve chatter is bad - it suggests the tolerances are way off, or a rocker has flaked and there is extra clearance as a result of the missing chrome.

What do I need to know about maintenance?

Four-valve Ducs are high maintenance machines, but everything is pretty straightforward. Follow the service regimen and your bike will last a long time – but neglect it and you will have serious problems. Here are some primer points on the unique steps in Ducati maintenance.

Valves – desmo valves need frequent adjusting due to their valve retaining setup. They use easily deformed half-rings to hold the valves in place, and over time these rings will shift and even break, changing the clearances drastically. A solution is replacing them with oversized, hardened collets from MBP (Canada) or EMS (USA) and matching shims, or if you are cheap and do your own adjustments reuse the existing half rings that have already been mashed into submission (assuming they aren’t broken).

It’s easy to learn how to adjust desmo valves, so don’t get scared off by the BS of arrogant mechanics. There are plenty of articles available on the subject (including one of my own) so I won’t bother repeating the process here. Suffice to say that the biggest problem is that you need a lot of shims – 16 in total for the desmoquattro, that’s 8 opening and 8 closing shims. So if you need to adjust a lot of the valves, it’s a pain to run back and forth to the dealer ordering different shim sizes. If you have the money, buy an aftermarket shim kit and save yourself some running around. If the valves are tight, you can get away with carefully grinding the existing shims down to the correct thickness; be sure to grind them evenly and accurately on some 400 grit wet sandpaper on a sheet of glass.

The cost of neglecting the valves are serious – too tight clearances will stretch, mushroom and snap the valve stems and bash the valve seats, and too loose will cause noticeably poor running, especially at low rpm, and put more stress on the valve train. Improper clearances will also increase the likelihood of flaking rockers and cam damage. So don’t neglect them.

Due to the nature of the design (closing the valves mechanically), desmo valves are hard on the seats compared to most conventional valve setups and the lack of spring tension to hold them shut at close means they are sensitive to leaky seats. To maintain optimum sealing the valves should be lapped every adjustment, but this means taking off the heads – use your own judgement on that one, I have never met anyone who lapped the valves every 6k on a street motor. Every 12-20k is a good compromise.

Alternator – the alternator nut needs to be checked every 6000 miles on all desmoquattro motors, moreso on later models which have looser tolerances on the nut. To check, you need to remove the left hand cover – early bikes used a now-unobtainable paper gasket to seal the left cover, later models just use Three Bond sealant. Most people just use the sealant rather than trying to track down gaskets, but on single-phase bikes you need to check the clearance of - and possible re-shim - the timing pickup on the LH cover if you are changing the way it is sealed.

Belts – Another area that should never be neglected, the belts are pricey direct from Ducati but cheaper from third-party distributors. CA-Cycleworks sells Exactfit belts identical to the OEM items for half the cost. Desmotimes carries Bucci equivalents. Replacing the belts is simple, but tension is critical, Always err on the loose side if you are doing it without the official tool (you should get it verified at a shop ASAP if you do so), otherwise the belt will snap very quickly. Again, never, ever neglect the belts, they are cheap insurance against an engine blow up.

Fuel system – as mentioned before, you need to keep an eye on the fuel lines and filter. If the filter gets clogged or the lines split, the fuel pump will work overtime and overload the electrical system, if the fuel flow doesn’t stop completely. So be prepared to replace the lines and filter ever 6000 miles or so, and make sure to avoid getting kinks in the lines. Something that can be considered is replacing the screw-type hose clamps with gentler snap-type clamps designed for high-pressure fuel injection lines – again, you can get these from Triumph for the 955i-1050 models. This will help prevent splits around the edges of the clamps. The o-rings on the disconnects are very easy to nick due to the design of the coupling (a very poor and fragile design that I curse often), and spares should always be kept handy because when they start leaking it’s a real pain in the ass.

Oil – obviously oil changes are important, but desmoquattros have an extra step in the process – check the strainer. The oil strainer is a gauze pickup that screws into the right hand side of the engine above the drain plug, and needs to be taken out every oil change to be cleaned and checked for metal flakes. Tiny amounts of metal or gasket material are signs of normal engine wear. Aluminum slivers, chrome flakes, or significant chunks of metal are bad news. The drain plug is magnetic and picks up swarf from the transmission, so it’s normal to find a few fingernail-clipping-like slivers of steel and steel fuzz. If you find a lot of steel material on the plug, either your shifting technique is atrocious or there might be something else going wrong…

Ducati says change the oil every 6000 miles. We say change it ever 2000-3000 (with new filter every other change, or 6K), and always use synthetic oil.

What do I need to know about tuning?

Ducatis have a wide variety of tuning options available, with plenty of nifty parts to empty your wallet. Here are a few areas of note.

Exhaust – You can’t have an Italian v-twin without freeing the sound of Italian thunder. Aftermarket systems come in two forms – full systems (very rare and very pricey), half systems (slip-ons from the crossover pipes up) and slip-ons. Different models have different exhaust diameters, from 45mm up to a max of 57mm on race parts. Bigger diameter exhaust systems don’t necessarily help power, in fact a system that is too big for the motor tuning will just make it run horribly and sacrifice a significant amount of torque and midrange power. There is a sweet spot for each model, talk to a Ducati tuning expert about options. Even a half system will free a fair bit of horsepower – 5hp at the rear wheel is easily gained on a standard machine with a proper fuel map, more is possible by uncorking SP, SPS or R models.

EPROMs – These are one of the great features of Ducati superbikes. Weber-Marelli fuel injection systems (P7 [851/888], P8 [916 Strada], 1.6M [916 Biposto and Senna, 748, 996*]) store their fuel maps on a replaceable microchip called an EPROM. EPROMs range in price from 40$ for OEM items or copied aftermarket chips, right up to 250$ for calibrated, aftermarket chips from specialists like Ultimap. Ditching the stock EPROM for even a basic unrestricted item (read: open exhaust pipe chip) will give a significant boost to the midrange and get rid of the 5000 rpm flat spot (put there for noise and emissions regulation testing). A new EPROM is a must if you replace the exhaust system, otherwise you will just hurt power delivery. Let your budget dictate what you want – a Ducati Performance open-pipe EPROM is cheap and will suffice for most street bikes, but if you want perfect fuelling you can always get a custom chip burned from dyno testing, or at least get a calibrated item from a respected tuner.

* Single injector mod (996) – The 996 uses double fuel injectors, and they are known for being a pain in the ass. Stumbling, flat spots, and on-off hesitation is a problem with the 996 fuel system, but it can be fixed by disconnecting the two secondary injectors and installing a single injector fuel map (often based on the Senna map, which was EPROM number 062, with some extra fuel added) in the 1.6M ECU. Search the net for a step-by-step guide. The best option is the Ultimap UM222, which is calibrated for a 996 running single injectors. Ed note - More recent investigations have shown that a good portion of the infamous 996 3500 rpm stumble is due to a significant spike in ignition advance right at that point. Solutions are still being experimented with. Disconnecting one pair of injectors is acceptable for a stock, street going 996 but any attempt to up fueling at high RPMs will result in a 100% duty cycle from the injector, which means the fuel mixture will max out and go lean as the revs build past that point. Once the injector is at 100% you can't add any more fuel. The max ceiling number with a single injector setup is supposedly 117-120hp at the wheel, which is of course rather hard to quantify and pretty vague. Generally if you do any mods to the bike (in terms of cams, pistons or overbore) you won't be able to get by with a single injector per cylinder.  

Intake – As I’ve already mentioned, the stock filters are your best bet for a compromise between airflow and engine protection. You will always get the best power from stock filters, as all EPROMs are tuned with stock filters in mind. If you are keen, BCM makes a modified in-the-runner filter setup, where oiled paper filters slide into brackets secured to the airbox openings. These filter better than the stock items, but they don’t solve the airbox seal problem, require airbox modification, and are expensive. In my unprofessional opinion you should stick to stock filters, they are cheap and work well enough under most conditions. Just check them regularly for dust entry and oil them properly.

Head work – One nice thing about 4V Ducatis is they feature hand-ported heads right from the factory. Combustion chambers are CNC machined, which gives a smooth combustion surface to improve fuel swirl and reduce hot spots that could lead to detonation. Porting should be left to the pros – they are very good from the factory and the only way to improve them is to reshape things pretty significantly.

Timing – Ducatis respond well to careful setup of the valve timing. This needs to be done by a pro with the right tools and the right ideas – different Ducati tuners recommend different timing specs. Sometimes just baselining the timing to factory recommended specs makes a significant difference; often the timing will be off a few degrees due to the loose tolerances of mass production.

Squish – Here again, mass production is working against you. Desmoquattros run at their optimum with about 1.00-1.05mm of squish, but most (except for a few hand built homologation specials like the 748R) are between 1.3 and 1.4 mm. On early bikes with a 1.2mm fibre head gasket, the easiest way to set squish is to remove the 0.3mm base gaskets and seal the barrels with Three Bond. If you don’t want to ditch the base gasket, you need to have the barrels shaved at a machine shop. On later models with a thinner head gasket and thicker base gasket, all you need to do is order some thinner base gaskets – on the 996, the base gaskets are 0.6mm thick, so you get 0.3mm items and you are set. Always make sure you check the squish properly, if you have less than 1.00 mm of clearance you will contact the head when the conrods stretch, causing catastrophic damage.

Cams – Lots of options are available for hot cams, 916/996 SPS items being the most popular. Standard 851-888-916-748-996s “Strada”  cams have identical profiles and are mostly interchangeable. S4 and ST4/S cams are Strada spec with slightly modified intake timing for more midrange. VeeTwo made high lift cams in various specs, FBF still makes them, and there are plenty of other aftermarket options. But always be aware of the drawbacks – you will lose low end and midrange power to gain top end, and higher lift mean more stress on the rockers and valve train. Plus your bike will need thorough tuning to optimize for the new cams. And they cost a heck of a lot on their own – cheapest I’ve seen is 1000$ for a set of stock, used SPS items. Take care when selecting profiles – some cams are not suitable for street use and REQUIRE the use of high compression pistons with deeper valve pockets.

Pistons – Once you’ve looked up the cost of a set of Ducati piston rings, you’ll understand why aftermarket forged high compression pistons are so popular – they cost little more than a set of OEM rings. There are drop in piston options for the stock bores, which is the simplest and cheapest way to up compression and refresh worn rings. If you want to overbore, 853 kits are available for the 748, 955 kits for the 916, and over 1000ccs is possible for a 996. But when you start messing with overbores, you are stressing the motor beyond its design and can seriously compromise reliability. Grenading motors are not an economical option for the street. It’s also advisable to rebalance the crank for different piston weights, and this means splitting the cases and generally going through a lot of trouble to do it properly – which a lot of people don’t. My advice is to avoid buying previously overbored bikes unless you reaaaaally trust the person who did it. And if you want more power, get the engine built by a pro. Speed isn’t cheap.

Flywheel – On 1.6M single-phase alternator bikes (with a single crank position pickup), the flywheel is a dead-weight item bolted onto the left hand side of the crankshaft – it isn’t used for timing purposes like most bikes (including the later three phase superbikes, as well as P8 computer’ed single-phase bikes with dual pickups). What this means is that you can completely remove the 2lb flywheel to drastically reduce rotating mass in the motor. This makes the motor rev hellishly fast – there is no more power than before, but throttle response will be really snappy and the bike will rev and reach the powerband a lot faster. Unfortunately this serious compromises the tractability of the motor, so unless you race or avoid slow riding entirely it’s not the best option.

Cranks – Crankshafts can be swapped between models to increase stroke. Almost all Ducati cranks from 1992 on are similar in design, even the 2Vs are the same as the 4Vs. Obviously you need a piston with a higher deck height to compensate for the added stroke, otherwise you’ll end up with a ridiculously low compression ratio (which, believe it or not, has occurred on some bike that had the wrong crank installed at the factory!). Putting a 916/996 crank into a 748 will give you 803cc. Putting a 900SS/ST2 crank in will give you 827cc. A 900/ST2 crank in a 916 gives 944cc, in a 996 it gives 1026cc, and so on. This is just with stock Ducati cranks – aftermarket options are available too if your wallet can handle it.

Clutch – Where to begin. Needless to say, the dry clutch has limitless aftermarket options, from lightweight clutch baskets to anodized pressure plates and springs and all sorts of ventilated cover designs. Less weight is always good, to reduce the rotating mass of the engine/driveline, but alloy and aluminium components in the basket and clutch pack will reduce the longevity of the setup  - the stock steel baskets and hubs can last indefinitely when they are taken care of. Clutch packs will last anywhere from 3000 to 30000 miles depending on how gentle you are on take off and how much stop and go riding you do. Some easy mods to do (that cost nothing) are removing two springs to reduce lever pull, removing the rubber gasket from the stock cover and spacing it with brass grommets (to let the noise out and air in to cool things), and routinely washing the clutch plates in soapy water. Flip the friction plates over on a regular basis to even out the wear - it’s a simple way to eek out extra miles from the pricey clutch packs.  

Suspension – the stock components on any Superbike are above average to really good. As with any bike, you can always rebuild the shock with a spring for your weight or get new fork internals, but the stock stuff is pretty good for majority of riders. Usually what your bike got was determined by what was on the shelf when it was being assembled. For example, some base bikes got an Ohlin’s shock, others didn’t. In general, the components respond very well to careful setup, much more so than most Japanese hardware. On everything except the base 748 models you get an adjustable steering head angle – this uses eccentric bearing races to adjust the steering head angle between 24.30 degrees (road) and 23.30 degrees (race). If you don’t know where yours is set, there is a quick check – see if you can lock the steering. In race mode, you can’t lock the steering head, in road mode you can. Also be certain the steering damper is correctly positioned – the rear mount is for road angle, the forward mount is for race angle. My former mechanic forgot to switch this after rebuilding my front end and I had a hell of a time trying to figure out why the bike kept pulling to the left slightly… There is also a rear shock linkage that can be adjusted to raise or lower the rear ride height. This should be left stock for most applications – that’s 261mm between the bearing centres. If you really want to sharpen up the steering, add a bit of length to the rod.

There are plenty of other things you can do, just look through a Ducati Performance catalogue some time to see how many methods Ducati has devised for emptying your wallet.

So why do I want one if it is this much trouble?

Well, the million-dollar question is always why do we choose a finicky, high maintenance, fragile Italian machine over a more reliable, faster Japanese machine. The fact is, these bikes are unlike anything else on the road. They were legends in their own time, they were championship-winning racers, and they offer some of the most fantastic feedback and road feel you will ever experience on a motorbike. The steel trellis chassis transmits information unlike anything else. Handling and road holding is fantastic, even 20 years after being introduced. The engine is smooth, and the power pulses of the big v-twin are easy to manage compared to the tyre-spinning thrust of a four cylinder. Ducatis are mostly hand-built, even today, and a lot of attention goes into the details. Despite their flaws, the motors are very solid and can handle a lot of power when maintained properly. And having one of the most beautiful bikes of all time doesn’t sound bad does it?

To be frank, we bought our bikes with our hearts, not with our heads. If you really want one, it doesn’t matter what the flaws are. They are brilliant machines and us owners are a die-hard lot. 


14 comments:

  1. I like your post and it is so good and I am definetly going to save it. One thing to say the In depth analysis this blog has is trully remarkable.

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  2. This is the most useful lot of information on this series I have found. I have done some of this stuff after buying my 996 2 years ago, given the considerations. Though not as informed as I would have been had I read this prior. BUT! Any further modification will begin with a reference, and thanks for that. You put a lot of time and thought into writing this and many people who have benefited most likely did not comment, so here is my comment. Great page and if you are still active in thinking about and working on these bikes please get a hold of me. Would love to chat with you and perhaps talk business: acusick@umich.edu

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  3. thanx a lot for the very resourceful info Sir.

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  4. Great article. I stumbled upon your site, and couldn't stop reading. I bought my 1997 Ducati 916 biposto in 2002. Any thoughts i ever had about buying a different bike were trashed whenever I started up my Duc. I will follow your site, and wish you the best on your journey. TC

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  5. Great info! I appreciate the thorough post. I own a 750 SS and have found it to be quite reliable. On a side note, I am convinced that Ducati's aren't as unreliable as advertised. I find Ducati owners tend to be perfectionists. If I doted on my Kawasaki the way I dote on my Ducati an outside observer would probably assume Kawasaki's are unreliable. Something to think about, at lest.

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  6. Hi
    Awesome article. Only thing missing to my knowledge is no mention of the cush drive rubbers popping out and grinding the rear hub to nothing, fixed with an aftermarket carrier.
    Thanks

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    1. Ah good point. I've never encountered this personally and it seems to be less common than originally thought. But it does happen in rare cases. Quick and easy check when looking at a bike is to glance at the back of the sprocket carrier, you can visually see if there isn't enough clearance. There will be metal flakes present if they are hitting the eccentric.

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  7. Hey there awsome read, just wondering if i was to put 748 sps piston and barrels on my 748 biposta would i need any further modification to the engine, eg con rods etc cant seem to find much info on this was hoping you could help regards david

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  8. Great post. I am concerned that you gave too much information though as this might put off owners. If I can balance it having owned one for 7 years so far. I am up to 49000 miles from buying the bike with 12 thousand miles on the clock.
    I started a blog from the beginning and the charging issue also affected me. I used the bike every day in the week and weekends. I eventually replaced the regulator rectifier for a mosfat r/r and have had no further problems. I have serviced it myself and can only think of 2 times it let me down. The clutch nut came undone. Fixed at the side of the road and had it tightened to correct torque when home. Another time the battery was flat and had to bump it. Not bad though.
    Vinnychoff

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  9. Legend mate, info greatly appreciated. Cheers

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  10. I love this article. I have a 1999 996 and over the 9 years that I have owned it I've experienced nearly all of the problems mentioned. The bike has nearly 50,000 km and despite the numerous frustrations with cooling, starting and falling over from kickstand failures, I've enjoyed riding it on the track, for daily commuting as well as long road trips(throttle lock helps with these;) and I honestly can't imagine owning/riding anything else. I have also enjoyed becoming intimate with the inner workings of the bike as I have done most of the repairs myself and compared to other bikes I've owned I feel like it was also designed and built with the mechanic in mind - as well as rider. e.g. what other bike can the body work be removed so quickly without tools. One thing about the article that surprised me was that there was no mention of the clutch sprague/starter failure. For a period of few months I was plagued with starting issues until I finally stumbled upon an article re: the starter clutch sprague spring which turned out to be the most satisfying repair to date because it cost me $0, merely snipping 3/4" off & re-attaching the long spring that holds the cams in place solved the issue and has held to this day. When this bike is well maintained there is no better sound than the roar of those twin pipes and what other 17yr. old bike will provoke people to cross from other side of street to take a closer look and wait around for me to start it up before carrying on with their day.
    996...es magnifico!

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  11. Gold Standard Desmoquattro Manifesto!
    Thank you for the taking the time to compose such a wealth of information.

    Eye opening as the information might be it shines a bright light into the mystery of maintaining such an exotic and passionate built machine.

    As a lifetime biker who just bought a 97 748, with my heart and not my head, I feel in great company. Ride safe and live with passion!

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  12. I just bought the 2001 996 and want to thank you very much for your post. This was very helpful, I will go home tonight to make sure I do not have any issues before I ride this weekend.

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  13. Excellent information thanks . My 95 916 has 1mm base gaskets and I can only obtained the Athena head gaskets S410110001008/1 do you think this is ok or will the compression ratio be to low . Regards Stuart

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