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Crank and Big Shells Replacemt Choice....

Posted: Thu Sep 09, 2010 2:51 am
by YPM25
Hi
I'm currently rebuilding my fzr600 engine. The shells are very worm and i have another crank so go in so i'm going to replace all the shells.

Trouble is yamaha have a list of 4 or five colour coded options. Without buying then all and mearsung the clearences is there a way of knowing wich ones to buy??

Many thanks
Ben

Re: Crank and Big Shells Replacemt Choice....

Posted: Thu Sep 09, 2010 4:34 am
by reelrazor
The cases are marked (series of numbers) and so is/are the cranks.

I know the Clymer manual has a breakdown about these numbers....I believe it is on page 135 (maybe 115??-I'm going off the top of my head here).

Re: Crank and Big Shells Replacemt Choice....

Posted: Thu Sep 09, 2010 8:25 am
by yamaha_george
reelrazor wrote:The cases are marked (series of numbers) and so is/are the cranks.

I know the Clymer manual has a breakdown about these numbers....I believe it is on page 135 (maybe 115??-I'm going off the top of my head here).
Yamaha have a stuff called PLASTISTRIP that you use to test what bearing shells you need in each position on a rebuild. IT IS THE ONLY WAY TO GET IT RIGHT (believe me I learned that quickly back in the '80's )

Re: Crank and Big Shells Replacemt Choice....

Posted: Thu Sep 09, 2010 3:43 pm
by reelrazor
yamaha_george wrote:Yamaha have a stuff called PLASTISTRIP that you use to test what bearing shells you need in each position on a rebuild. IT IS THE ONLY WAY TO GET IT RIGHT (believe me I learned that quickly back in the '80's )
The whole wide world has Plastigauge. And you are right Geo, it is the only way to get it right.

What I am saying is that now with the crank and case numbers- he can make an educated guess and drastically narrow down his a)- choices of (FIVE sets) replacement shells to THEN plastigauge b)and he can minimize the monetary hit he will take on proprietary bearings shells($45 per set here in the states-buying all five sets sets him back $220).

Re: Crank and Big Shells Replacemt Choice....

Posted: Mon Dec 13, 2010 9:38 pm
by DonTZ125
If I might resurrect this thread...

There's a young fellow on FZR250.com who has just migrated to the Archives in search of help sizing crank bearings. His crank vs case numbers are WRONG, and my guess is that a PO had replaced the crank at some point. When crank and journal are marked as Size 2 (2-2 = 0, not a bearing choice), what is he to do? If the cases were line-bored to accept a properly-clearanced journal shell, or the crank was re-ground, how can he tell what bearings to use?

Has anyone figured out the Yamaha colour-coding system yet?

Re: Crank and Big Shells Replacemt Choice....

Posted: Wed Dec 15, 2010 10:05 pm
by racerd14666
off the top of my head it think its 0 White 1 Blue 2 Black 3 Brown 4 Green 5 yellow

Re: Crank and Big Shells Replacemt Choice....

Posted: Thu Dec 16, 2010 1:44 am
by DonTZ125
Hi, racerd.

That's what I thought, but the problem is that his numbers are out of range. His case numbers are 227558; his crank numbers are 221122, leaving bearing numbers of 006436. Not many bikes use 0 = White, and I've NEVER seen a 6. The 3LN bikes only use bearing #s 1-5; what then does he use for 0 and 6?

My thought is that this isn't the crank his engine left the factory with. Short of finding a crank that better suits his cases, what can he do? Can he run 115435 bearings without them spinning instantly? What happens if his current crank has had the journals previously repaired?

What are the actual thicknesses of the various colour codes?

Re: Crank and Big Shells Replacemt Choice....

Posted: Thu Dec 16, 2010 9:08 am
by yamaha_george
yamaha_george wrote:Yamaha have a stuff called PLASTISTRIP that you use to test what bearing shells you need in each position on a rebuild. IT IS THE ONLY WAY TO GET IT RIGHT (believe me I learned that quickly back in the '80's )
So why are we still asking the wrong questions ?