Oldfeller--FSO wrote on 07/15/12 at 05:01:07:

The knock sound was the original '88 engine, that one had a burnt piston with seized rings.  The knock sounded low, but I traced it up to the piston.
The '02 engine with the failed bearings made an occasional whine.  Then finally failed with a ratta ratta sound as the CB smacked the bottom of the jug.

 
you got a pic of the cam sitting in the journals -- both are fine

Good news, you had no oil pressure issues at all and you can quit worrying about oiling issues and wear due to same.   All the stock cams have the heat treat black oxide left on them intentionally by Suzuki (cheaper that way and they can claim it holds an oil film better than a dry smooth ground part).  

I shined mine up .... goal is to reduce start up wear on the cam bearing surfaces after all.

Lateral movement in the rotor means that the crank is not being located correctly by a completely trapped huge ball bearing and a heavily clamped piece that indexes off of that trapped bearing.  

Guys, check me on this, the lateral clamp up for the crank comes from the primary gear retaining nut by the cam chain, that big assed left hand threaded nut that holds on the primary gear and cam chain sprocket is the controlling side that tells the crank where to spin lateral wise..

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The crank is not supposed to float or move laterally nor are any of the pieces associated with the crank supposed to be floating around laterally.

Somebody at the factory screwed up and didn't tighten something (if the big nut is allowing movement) or they didn't install a bearing retaining plate correctly (if the big assed ball bearing is moving laterally in its machined race).  Or the machined hole is oversized/over deep and it is not holding on to the bearing ...

Time to go get the Clymers manual and see how it really is supposed to work .....


Yup, right side big assed ball bearing on the crank is trapped by a bearing plate and has a major torque value on the left hand threaded nut that traps all lateral motion on the crank/rotor assembly.

Ditto for the counter balancer assembly, big bolt on the right side pulls it tight against a bearing plate retained big assed ball bearing so it can't have lateral motion either.

 
Four possible sources for a vertical motion as you describe.


Standard internal radial clearance of the ball bearing itself on that side (very very small movement).    There is a check spec for the ball bearing itself from the bearing mgf and I think the test v block specs in Clymers should reflect the wear limit for the same item.

Broken ball race cage in that bearing, allowing the balls to move to the sides thus permitting the crank to move up/down more than the standard internal radial clearance of the ball bearing itself.

Ball bearing pocket mis-machined (oversized) allowing entire bearing outer race to go up down.

Wrong bearing (ID or OD)




Every time the crank counterweight rolls up or down that motion is gonna take place -- this would be in time with the sharp knock sound you were doing at the Dragon.   The noise will increase as the room to move slowly increases.



Here are the faces of the Dragon folks listening to Dave's knock ....   Once you stuffed rags into his pretty loud muffler to shut it up you could really clearly hear the sharp knock even at idle speed.

 
Did you see any signs of the counter balancer weight clipping the cutout in the jug?

This happens when they are installed with the timing incorrect or they get wonky when a bearing ball cage lets go and the weight starts to wander a bit ....

What is so rough around the edges? Or is it from the casting?

Well I got my puller and removed the alternator rotor and starter stuff.  The next thing holding me back was the 46mm nut holding the flywheel on.  I could not find any friends or relatives with a 46 mm deep socket.....but I found a $ 7.99 shallow one at Tractor Supply.  I have a meeting tonight and just had enough time to cut the socket in half so I can extend the depth, and when I tried the fit on the nut with my fingers.....the nut spun!  The nut that is supposed to be torqued to 100 ft. lbs. was finger tight!

Now I have to figure out if the loose bearing allowed the nut to shake loose - or if the loose nut was causing the problem.  I imagine the flywheel was shaking back and forth a bit and making noise.  I tightened the nut with a big crescent wrench, and I am still getting some play so I suspect the bearing still has some play in it.  I need to go to a meeting.....so I won't get to work on it any more tonight.  Tomorrow night I might get to take it the rest of the way apart.

I agree. Those bearing and roller surfaces aren't looking really great, but should not be the reason why there is so much play. Me thinks that the whole bearing was out of tolerance from the factory. I guess you got the "Golden Ticket" so to speak.

You have to turn your macro on if you want to do close-up pictures. There should be a button with a flower on it.