999 engine vibration

I have an 04 999 thats developed heavy vibes at high revs, say from 7k upward. Its done 14k and hasnt had a hard life. The whole bike has been apart down to the last bolt recently because all the paint fell off it. Heads have been off and reshimmed to perfection, the rest all checked over and rebuilt with new gaskets etc. And paint, lots of it. All of this was done by myself so I know (Im in the trade) that its spot on. I dont tend to give it too much death (frightens the life out of me if i’m honest) but I wound it right out last weekend in a safe and legal area of course and the vibes thru the bars were unbearable. I’m sure it wasnt like that before…

Anybody come across something simliar???

Not something I have heard of

Just a thought, but are the engine mounting bolts all tight?
Doesn’t sound right, though?

You say the whole bike’s been apart down to the last nut and bolt…You’ve re-shimmed the heads, what else did you do to the motor?
Have you balanced the TB’s/throttle bodies and if so at what revs?
My 851/916 (that kicks out 999 power and some) gets smoother the higher it revs.

Steve R

I always noted these motors for being smoother than they should be.
The engine was pulled apart for cleaning and painting. Checked the bores and pistons for wear, cleaned up and rebuilt with new shims and gaskets. Didn’t split the casings because there wasn’t a problem as far as i was aware. Kinda wish i had now, have been pointed towards worn mains. Have to say I would have expected to hear worn mains or noted signs of piston contact. Regarding balancing the throttles, I gave it to a Ducati specialist in Leeds because i’m not familiar with this (Im a diesel man) induction system. He adjusted the TPS (was cutting out when hot, the usual) and balanced the throttles for me. Don’t know at what revs though. Also set the belts with the harmonic gauge (already just about spot on apparently) I’m gonna check the alternator bearing (again) when I get a minute. Not really, i’ll probably just drop the motor again.


Before you drop the motor again, check the mounting bolts are fully tight as Kev suggested.
If it’s still vibrating remove the alternator cover* (not just the little plate covering the outrigger bearing) and try to move the crank up and down, any movement will point to the main bearing being worn or F’cked. It’s usually the flywheel side main that goes 1st.
I balance the TB’s at around 4-5,000 rpm using vacuum gauges, setting them at idle isn’t good enough.

You’ll need to drop the coolant to do this, it’s not necessary to drop the oil if you lean the bike to the right, I put t 1" piece of wood under the L/H side of the paddock stand.
BUT I’d drain the oil into a clean container, (you can reuse it
*) then check the magnetic sump plug and oil pump screen for debris. If the mains are breaking up you’ll probably find a small metal “hedgehog” on the sump plug.

** If the oil’s only down a few hundred miles, I poor it back into the motor through a couple of sheets of kitchen roll lining the funnel.

Steve R

Thanks for the advice, i’ll report back as and when…

Following up on the previous post, if the shells are breaking up the particles are not magnetic, so you’re more likely to find them on the mesh filter than on the sump plug. They’ll look like gold flakes - highly shiny and gold in colour. Ducs tend to be ‘buzzy’ rather than have strong vibrations; the latter is definitely not normal.

If the shells were failing the big ends would be knocking like the hammers from hell, loong before the shells actually broke.
I’ve never known shells to break up? Rather/usually they wear out and knock, because of this I’ve never found any parts/flakes of them on any screen or in any type of filter.
Failed main bearings tend to rumble and the motor starts to vibrate, the more the wear the louder the rumble and the more vibration is felt IME.
I’ve blown up a few motors over the years with both big end/Shell and main bearing failures, I’ve also rebuilt an awful lot more for other owners, so I’m fairly confident that I know what I’m talking about here… :wink:

Steve R