bad vibration

[300racer]

i just got done rebuilding my motor and it runs great but for some reason it has a bad vibration. the more you give it gas the worse it gets. i had something close to this happen b4 and it was a cracked crank bearing but i didn't touch the bottom end this time and it didn't do this b4 i tore it apart. i did put a new timming chain on and was thinking maybe i don't have the fly wheel on wright but is it even possible to put it on wrong? any info would be helpful.

[Jason Hall]

Did you have the clutch cover off??? If so did you maybe miss align the counter balancer marks???

[300racer]

i had the clutch cover off but i didn't take the counter ballancer off. are there marks on the clutch basket and the counter ballancer? if so that is prolly the problem. i hope thats what you are asking me. lol

[Scro]

Originally posted by 300racer
i had the clutch cover off but i didn't take the counter ballancer off. are there marks on the clutch basket and the counter ballancer? if so that is prolly the problem. i hope thats what you are asking me. lol

There aren't any marks on the clutch basket. It doesn't matter which way you put it in. The counter balancer does have marks.

[300racer]

thats what i thought. i was waiting on you to reply scro i have not seen a question you couldn't answer lol. this isn't looking good.

[Scro]

I can't think of much that would cause that much noticeable vibration in the topend. Make sure your cam chain tensioner isn't locked in the loose position.

[fastredrider44]

Originally posted by Scro
I can't think of much that would cause that much noticeable vibration in the topend. Make sure your cam chain tensioner isn't locked in the loose position.

That would make a bunch of noise. I hate to guess what it could be, but it's probably not good.

[300racer]

well i took the fly wheel cover off today and don't know how this happen but the relief valve had fell out some how? i didn't touch that either :confused: but don't know how that would make it vibrate. and i checked the counter ballancer and it seems to be off also? i don't even have the tools to take that out so i don't know how it got turned?:confused: maybe i shouldn't have bought this bottom end. lol what does the relief valve do any way?

[300racer]

have the ballance off and took the bearing out of the right case and it came out with my fingers. is it supposed to be pressed in there or does it just fall out? the ballancer had alot of play.

[Jason Hall]

Sounds like the balancer has been out of time for a while, and might have beat the bearing bore out. Does the bearing have 2 retaining bolts with small plate's that butt against the outer race of the bearing? If so, It's probly not pressed In Real tight, but should need to be tapped In lightly. I have bored cases, and Istalled steel sleeve's becauseof that type of problem. I would buy a new bearing, and see If It fits tighter than the one you removed. If It's still very loose, then you might want to do something about the worn bearing bore.

It's possible that the vibration caused the clip In the relief valve to pop out of It's place. Or maybe who ever was In the engine before did'nt put the clip In with the sharp edge facing outward. An Internal and external snap ring has a sharp edge, and a rounded edge, most people don't know this. The sharp edge faces outward so It can catch the groove to hold whatever Is behind It firmly.

[300racer]

thanks for the info. is it very costly to have the bearing bore fixed? and who does it? i went to a local bearing dealer and he said he didn't have the size bearing that was in it. he had some very close but the out side race was a little bigger and would have to be pressed in the whole.

[Jason Hall]

I have Lots of machine shop In my area that build parts to supply the big 3 auto maker's here In Michigan. You would need to split the cases In order to lay the case flat on a mill table. Then the bore can be sleeved. Might want to see exactly how much bigger the bearing Is that your supplier has, as you could possibly bore the cases to that size, or simply press It In. Just make sure when the new bearing Is pressed In that It does'nt crush the Inner size down to small. I'm sure I could get the case fixed for you If It came down to that. I can't see It costing more than 40-50 bucks to have It repaired.

Jason.