Tuesday, March 17, 2015

BMW R1100R 100-Thousand Mile Service

Here is an R100R that recently (4000 miles ago) had the clutch replaced at a local BMW dealership.
Apparently they missed a few things while it was apart and those items will be detailed here.
Keep in mind that until now the bike had always been serviced by the same dealership, at the factory recommended service intervals, which makes what I found all the more inexcusable.

This is the point to which the bike needs to be stripped to replace the clutch.

Starting from the final drive (which is the first component to be removed) we find that the outboard Paralever pivot bearing was seized which caused the inner race to destroy the pivot pin.

This is the outer race from the outboard side.  Obviously both bearings and the outboard pivot will be replaced.

The final drive seal was also leaking and was replaced.

Moving up to the swingarm pivot we find that both swingarm pivot bearings are failed.

The above items are things that any competent mechanic should have checked and found during the course of the clutch replacement procedure.

Since the transmission is out of the bike and considering the mileage, the transmission was resealed and the clutch release bearing, spring and boot were replaced.   BMW transmission seals do not rely on a shoulder to seat against, so they must be installed to their proper depth using a shouldered driver.

The input shaft, note the spline wear at 100K miles

Resealing the output shaft

All of the rubber parts will be replaced (right down to the battery strap) since they are subject to age-related deterioration.  The bike is also getting a set of Wilber's shocks to replace the OEM dampers that are well past their best days.

Friday, February 20, 2015

Desmoquattro Valvetrain Condition at 20K

Here we have the pinnacle of race engine cylinder head technology, circa 1955.
Physically huge, large included valve angle (for a 4-valve), obsolescent desmo valve drive, ball-bearing supported cams, it's all there.
Actually it's a cylinder head from a 2005 Ducati ST-4 with roughly 20 thousand on the clock (although that doesn't make the above statement any less true).

The valvetrain geometry of the Desmoquattro forces tremendous side loads on the valve stems during the opening sequence.  As one might expect, this is a very tough environment for valve guides and stems.  In a race engine that is serviced as often as it's ridden this isn't really an issue since race engines are expected to have a short lifespan.  This is precisely why using this engine in a road bike isn't the best idea and using it in a touring application is patently absurd.  Make no mistake, the Desmoquattro is a race engine, designed in the 80s to win WSBK races.

In the following photos and video you will see the effects of mileage upon this design.  Keep in mind that although 20K isn't a lot of miles on a street engine, it is multiple lifetimes for a racebike-derived engine.

Testastretta engines are far more tolerant of street use precisely because their valvetrain geometry imposes far less side-loading on the stems due to their narrower included angle and much-improved rocker arm geometry.

It isn't just the valveguides that suffer.  Here are the closer shafts and springs.  Note how the closer springs have worn notches into the shafts.  Also note the wear to the spring wire itself.  This wear is exactly where the springs will fail.  The notches in the shafts are also stress raisers and will result in cracking and failure of the shaft at some point.

In this video the amount of valve guide wear is evident.

Since this is an obsolete engine, there is no aftermarket support except for shims and exchange rocker arms to correct the notorious chrome flaking.  This means that one either has valves custom made or you pony up the 150-200 dollars PER VALVE for OEM.
Buyer beware.

Saturday, September 27, 2014

Scrambler?.... Cafe Racer?.....

...Yes, it's both, or maybe neither, but it is pretty cool. 
It started life as a 1976 R75/6 that now wears dual-plugged heads,  BMW 336 performance cam, Dyna coils and electronic ignition, bobbed stock mufflers and many other custom touches.  The bike's owner did the vast majority of the custom work including the paint.  Motorrad Werkes handled the engine and chassis mechanical work for this one-of-a-kind project.  The owner is justifiably proud of his creation and we thought the finished product was worth sharing.

Friday, August 22, 2014

Multistradas and dirt...

I'm not going to get into whether the MTS1200 is a real "ADV" bike or not.  Each owner will use it as they see fit.  I would like to address a couple of points that should be given some thought if you do use your bike off-road.

First are the timing belt covers.  Ducati actually puts a foam filter in the front belt cover, apparently to prevent dirt ingress.

This is a sensible approach since dirt or other debris in the timing belts can never be considered a good thing.  Unfortunately the effort is for nothing because the rear belt covers do not even meet.
Take a look at the gap between the upper and lower halves of the rear belt cover.  So much for that idea.

Next up is a lesson in how not to design an airbox.  The air filter is a trapezoidal tube, open at each end.  It is constructed of pleated paper and has rubber gasket ends.  The left end sits up against the inside of the airbox and the right end is captured by the airbox snorkel.  The seal at both ends depends solely upon the compression of the rubber seals.  Here is where the problem arises, what do you think happens when that filter retainer is tightened down upon the PAPER filter.  Well, what happens is that the entire filter compresses thereby allowing leakage past the end seals.  Here are some photos of the "clean" side of the airbox.

In the second photo you will notice a few things.  First is that there is no register or shoulder to positively locate the filter element.  Second is the paths of dirt that have leaked past the filter seal.  Third is the homemade "improvement" via a soldering iron.  This is apparently a popular modification on internet forums, along with removing the external air supply to the airbox.  While I've not flowbench tested a modified vs. stock MTS 1200 airbox, I'm pretty sure that that sharp-edged ragged hole has succeeded in nothing beyond destroying the airbox's rigidity and therefore its designed-in resonance.  Removing the duct that channels cool outside air to the airbox certainly is not a way to increased airflow since the now cut-off snorkel is sharp-edged, and airflow does not like sharp edges.  But who am I to argue with internet experts.
I have compared a number of popular "free HP" airbox modifications for other bikes that are popular on the net.  Rarely do they work as touted.  One example is removing the rubber inlet snorkel from the airbox on the Aprilia Caponord.  This results in a sizeable DECREASE in airflow due to the fact that the airflow is encountering a sharp-edged hole and becoming choked by turbulence.  Many armchair horsepower junkies believe that airflow behaves intuitively, IT DOES NOT.  Unless studying airflow is your hobby and you have pretty good grasp on fluid dynamics and the effects of Helmholtz resonance, you should probably rethink cutting, drilling, sawing or otherwise mutilating your airbox.

Monday, August 18, 2014

DIY Special for September

Here's a deal for all of you guys who like to change your own oil.

For the month of September, buy a Ducati OEM oil filter for $15.95 and get your service reminder reset for an additional $15.00!

Don't use an oil filter of inferior internal construction just to save a couple of bucks, this is false economy.  Your premium machine deserves the filter that was designed for it specifically.

Thursday, August 14, 2014

Multistrada 1200 Major Service

This MTS1200 is in for its 30k service, belts, valve adjustment, etc.  Once you excavate your way to the engine the service procedure is the same as for any Testastretta so I won't go into exhaustive detail regarding those items that are common to all 4V Ducatis.  There are a few items that I will point out, some that are unique to the Multistrada.

First is the sheer number of fasteners that must be removed to facilitate servicing.
Second is the cramped quarters while servicing the rear cylinder head.  This area is much more accessible in the Superbike chassis.

On the other hand, the MTS chassis does offer much more room to work on the front cylinder thanks to the taller suspension and the high-mounted oil-cooler.

Here is some advice for those owners who like to change their own oil and filters.  If you install the drainplug so tightly that this happens when removing it, then you're overtightening it.  Buy a good torque wrench and use it.  The same rule applies to the filter, if it takes an extension on the filter wrench (it did) and collapsing the filter body (also, yes) to loosen the filter, then you overtightened it.
If you're paranoid about losing an oil filter, then simply put an ordinary hose clamp on the filter body and orient it so that it prevents the filter from unscrewing.  Do NOT use one of those aftermarket billet filter clamps.  Their design does not allow for uniform clamping pressure around the filter body.  They will actually crush the body AND be loose at the same time.  Just use a hose clamp.

Now let's talk about an aftermarket item that actually does what it says it will do.  Whether or not this is actually beneficial is another story.  FatDuc O2 sensor signal manipulators intercept the oxygen sensors' signal and send a modified signal to the ECU, causing the bike to run richer than stock in the closed-loop portion of the mapping.
As can be seen by looking at these plugs, the fueling is quite rich.

Saturday, July 19, 2014

An expensive lesson

European (and especially Italian) motorcycles are much like a high-maintenance girlfriend, they don't tolerate neglect and if you're foolhardy enough to neglect her needs she WILL make you pay.
In all seriousness, European motorcycles are very expensive to own and maintain, with Ducati and BMW heading the list.  Many prospective and first-time Ducati owners are shocked to realize that they will be facing maintenance costs of 600-1200 dollars (depending upon exactly what is needed and who does the work) EVERY 6500-7500 miles. This maintenance simply can not be deferred as these bikes will not suffer neglect the way that some other bikes can.  It is simply the cost of owning an exotic vehicle and something to keep in mind if you're contemplating the purchase of a bike like this.

Here we have a 2003 Ducati 999 Monoposto, looking very seductive in her bright yellow dress and carbon fibre jewelry.  Hot, yes?  It has 13,000 miles and is due for its second major service.  Apparently the starter clutch started playing up and rather than getting it taken care of immediately, the owner put it off until the sprag failed completely.  The extent of the damage is detailed below.

Here is the alternator cover ready to be removed.

Once the flywheel was removed, here is what was found.

After cleaning everything, the full extent of the damage becomes apparent as the gear and the outer race are also destroyed.

Here is the new starter gear, compare to the failed gear in the second photo.  Yes, much of the metal that used to be that gear ended up in the oil.

Here is the new sprag and flange ready to be assembled to the flywheel.

Here I will show just how easy it is to screw things up if you aren't careful during assembly of the flywheel/sprag/gear assembly.  In these photos only the bearing and spacer are shown for clarity.
There is a thrust washer that goes between the crankshaft timing gear and the starter gear.  The inner bearing collar MUST pass THROUGH the thrust washer when assembled, as shown in this photo.

When it is correctly assembled on the crankshaft, it will look like this.

If the thrust washer slips off during assembly, this is what will happen.  Note that the washer is off-center and is trapped between the bearing collar and the crank gear.  If the flywheel nut is tightened with this condition present the thrust washer WILL FRACTURE and also relieve the torque on the flywheel nut, causing much damage.

The correct way to reassemble the assembly is this, use some grease to hold the thrust washer in place and rotate the starter idler gear while sliding the assembly onto the crankshaft splines.

Speaking of splines, you can't just slap the flywheel onto the crank any old way.  The oil hole in the flywheel must be aligned with the large groove in the crank.

The last step before closing up is to reinstall the alternator rotor.  Contrary to what the manual says, the rotor bolts must be replaced.  The updated bolts are class 10.9 whereas the old-style bolts are class 8.8.  There is a considerable difference in strength.  They also should be thoroughly degreased and Loctited and torqued to proper spec.  I assemble the rotor to the flywheel with the flywheel installed because it's easier than doing it on the bench.  The stock flywheel nut is only temporarily holding the flywheel.  The final assembly is with Nichols double nuts, Loctited and torqued to 140 lb. ft.

 I will not go into replacing the belts, etc in this post as that procedure has been detailed elsewhere in this blog.

One final note: 
There is a lot of talk on forums about shortening the sprag spring or replacing it with the spring from some seal or other, in order to prolong the life of the sprag.  This is nothing less than butchery.  If you can't afford the parts, maybe you shouldn't own a Ducati.  If you take the bike down this far and don't do the job right, maybe you shouldn't own tools.