Ducati Desmoquattro Superbike FAQ – So you want to buy your dream bike…
What’s good about them?
Well, many things. Most people tend to agree that the 916 series is a groundbreaking model and will remain a classic motorbike for years to come. This ensures good resale value (bad for buyers, good for sellers, heaven forbid you should actually sell it) 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 entire bike. 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 as well as together. Beyond the good looks, these bikes are good 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 again. 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 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 overheating 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.
What goes wrong?
Electrical – the pre-1999 charging systems are completely inadequate. The 916 uses a piddling 350 watt alternator that cannot keep its 16 AMP battery charged without regular hook ups to a trickle charger. The 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 crankshaft and alternator damage, so it needs to be tightened regularly. 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. 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, because water gets into the connectors and corrodes them.
Things that break – Some 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. It’s cheap to replace, around 20-30$, so keep an eye out for leaks and fix it ASAP.
2. The plastic airbox on early models (pre-1999-ish) is a bit thin and commonly cracks along the creases of the plastic. This isn’t really anything to get upset about, just seal the crack with black silicon. You can always put on a later airbox or if you have the money get a carbon fibre replacement.
3. The triple trees and clip-ons can crack – this is a serious problem and if it pops up it needs to be fixed immediately – you don’t want a fork to fall off or a clip on to snap while you are riding.
4. The rear wheel spindle was recalled for the potential to develop hairline fractures – dealers were supplied with an ultrasound machine to check for invisible cracks. Make sure this has been done.
5. The oil pressure switch (or “sender unit”, located ahead of the clutch cover) commonly fails. It will usually start setting off the oil light intermittently, and oil will seep up through the switch. Obviously if the oil light starts coming on, check the oil pressure right away – if it is within specs, then your pressure switch is to blame. Replacements are 5$ from UAP/NAPA.
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.
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.
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 loctited to makes sure they don’t fall off on the go.
1. The fuel tank 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 about ¼” 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. Immediately tighten the bolt when this happens before the sidestand falls off. I recommend safety wiring the bolt in position, as it tends to get greasy and loctite isn’t very effective on a short thread that gets saturated with oil, dirt and grease.
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 (its part of the reason there is really bad driveline lash at low rpms) 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 replacing it will help smooth out the power delivery a bit.
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 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 in Quebec) because you WILL break at least one in your period of ownership. 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.
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 they should be 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 crankshaft 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 to see if it is happening. 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 threadlocker red. It’s a 2$ plug 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.
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 will likely 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. If you are paranoid (like me) replace them ever 6 000 miles. OEM items from the dealership run around 70-80$ apiece, but you can buy identical Bucci belts from third party suppliers for around 30$ each.
Crankcase breather – Ducatis have a fair bit of crankcase pressure, and respond well to large breather boxes to reduce pressure to atmospheric levels or better yet, a vacuum to help pull the pistons down. On race bikes, double breathers and large volume 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. Also make sure you don’t overfill the oil above the max level, as it will increase the likelihood (and amount) of oil misting.
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 – when the pickup sucks air, you might as well be running without oil. 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 stressed chassis member secured in the frame, with a rubber seal between the two. 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. 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 - dyno tests prove a LOSS of 3-4 hp compared to stock filters. 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.
Drops – Ducatis are fragile machines, and a simple drop in the garage will mean thousands of dollars in damage. 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 “suisidestand” 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 or face the consequences.
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 synthetic is 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. When cold, the motor takes up to 90 seconds to circulate oil to the heads because of the lack of one-way valves in the oil lines, and a long circuit for the oil system. So let the motor idle for at least 90 seconds (or better yet, until the temp guage hits 140 degrees) before touching the throttle, otherwise you may exacerbate the rocker arm flaking issue.
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 big block with a broken conrod, or as the sound of a shot crank bearing. To me it sounds like terminal piston slap. 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 rubber 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.
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 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/dry sandpaper.
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. Ever.
Due to the nature of the design (closing the valves mechanically), desmo valves are hard on the seats compared to most conventional valve setups. To maintain optimum sealing the valves should be lapped every adjustment, but this means taking off the heads – this is fine on early (pre 1999) bikes that use fibre type head gaskets that only cost about 25$ each, but a bit of a pain on later models that use 125-150$ a pop copper gaskets. So use your own judgement on that one.
Alternator – the alternator nut needs to be checked every 6000 miles on all desmoquattro motors, moreso on early single-phase bikes with the stator bolted to the crankshaft. While the 520 watt three phase system of 996s and later 748s is different, they are still prone to loosening their alternator bolts and causing serious damage. 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 Bucci belts identical to the OEM items for half the cost. 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 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 ever 6K), and always use synthetic.