$64000 Question...

[2 Wheel Wanderer]

Today I said screw it and tore the engine town to the cases. Heres what I found...

Horizontal Cylinder - Its like this on the top and bottom



Vertical Cylinder - Its like this in front and rear.



Here's a video of the rods, I am able to wiggle them pretty good back and forth. No sound, my cameras trippin but you can see.
Duc Rod Play

[booger]

Well the crosshatching still looks intact, but the rod play looks bad. Not sure if that is the cause of your vibration problem since I'm not sure if the rods are supposed to have some play or what but perhaps a rebuild is in order now. Source a 900ie engine and do an upgrade [moto]

[2 Wheel Wanderer]

I wish I could do an upgrade but I am low on funds and would love to just get this thing back on the road without spending too much cashola. If the cylinders and rods are ok I need to dig deeper to find the problem. For some reason my gut is telling me that if its not the rod play that its a bearing. When I turn the crankshaft it is kinda smooth but I hear a weird creaking sound (in neutral, out of gear).

Edit: So one more thing that found, on one of the cylinders the ring gaps were all almost in a line. They should be 120 degrees apart. Could this be the problem?

[kingmoochr]

no, the rings rotate around the piston while the engine is running. the rod should not be able to wiggle in the way you show that much. how many miles on this motor? ive only heard car motors with rod knock, not totally convinced it'd result in a vibration. i do suppose it is much more likely to do so on a twin.

[2 Wheel Wanderer]

38K on the motor, here is my last thread http://ducatimonsterforum.org/index.php?topic=39360.0
theres a full background on the bikes troubles in the beginning.

[Howie]

The gaps need to be at 120^o, you will have blow by if they are in line.  You didn't say what engine you have, but you do have full floating wrist pins, so you will get some wiggle.  If you have a 750, you are allowed a max of .025 mm between the wrist pin and piston, .05 mm between the rod and wrist pin.  Assembly tolerance are tighter.  

What is the noise like?  Deep thud?  Light rattle?  Metallic rap?  At what engine speeds?  You did check for a loose flywheel nut, didn't you?

[Howie]

Oh, I just read that thread.  you are not after a noise, you are after a vibration.  Did yiu do a leak down or compression test before disassembling? 

[Duck-Stew]

Vibration?  It's your rings.  Re-align them properly and put it back together & go terrorize your neighborhood some more.

Rod 'wiggle' doesn't look excessive to me, but the quality of the vid and my player ain't the hottest and there's some gin in my bloodstream right now.

[2 Wheel Wanderer]

Motor is a 620, compression test was at 150/153 psi and in the leakdown test showed 18% air loss out of the rings, nothing out of the valves. The manual states that the axial play between the con rods and the crankshaft should be 0.15 – 0.35 mm, I'll have to measure that tomorrow. The wrist pins came out perfectly, no play at all.

[2 Wheel Wanderer]

Vibration?  It's your rings.  Re-align them properly and put it back together & go terrorize your neighborhood some more.

Rod 'wiggle' doesn't look excessive to me, but the quality of the vid and my player ain't the hottest and there's some gin in my bloodstream right now.

The vid does suck! But its all I could give ya. Ill give er a go with the rings realigned and see where we are from there, thanks Stu.

[Duck-Stew]

If you did a valve adjustment recently and got a shim wrong, that could cause a vibration...

[koko64]

If this isn't correct, sorry to aggravate your grief.

For vibrations through the pegs I would first check the footrest hangers and anything associated with them. You probably have already. Also check the drive train (sprockets, chain and cush drive components) as has been suggested. A check of the flywheel for any loose bolts could be done easily buy running the motor and checking the timing window with a flash light or timing light for any wobble/runout. Also holding the clutch cover or putting an ear to it for any strange vibration or noise might ascertain if your clutch assembly is loose before taking off the cover.

If you have done all this, sorry mate and I hope its nothing too deep in the engine, i.e bottom end.

Like everyone else I'll be watching with fingers crossed!

[Howie]

Vibration can be a pregnant dog to find.  I watched one of the best in the world chase down a vibration on a Monster.  After checking engine tune, valve clearance, carbs, flywheel nut, etc the vibration was traced down to the home made license plate bracket used in the tail chop.

[2 Wheel Wanderer]

Hey all, so I reset the ring gaps on the pistons and it did make a difference but the main vibration is still there.

FYI I tore a bunch of ligaments in my foot and haven't  been able to walk for 3 weeks. So I was finally able to walk yesterday and work on the bike. I took off both engine side covers  and all was good on the flywheel side but on the clutch side I was able to wiggle the clutch basket and the big primary gear a bit. Is this normal?

[DucHead]

No play in mine.  I'd torque all fasteners to spec and try running it.  If the basket, etc. are loose, I would think that would cause some pretty large vibrations.