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Discussion Starter #1
Does anyone here know difference in length between the 99-00 and the 01-02?

I don't have a 01-02 motor torn down at the moment, and was trying to avoid ordering a rod (or piston) just to measure. I posted this question over at the WERA board, and got a couple of conflicting answers.

I'm de-stroking a crank, and am trying to avoid having custom rods made. I'm going to mill the cases to bring the deck height back, but was thinking I could make up some of the difference with the 01-02 parts.
 

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Discussion Starter #3
Thanks, but I'm building this one out of a 2000 motor.

The rod length (and pistons) changed in 2001, and I was looking for specs. of those parts.
 

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Discussion Starter #5
Thanks dennie, I kind of knew it would be a shot in the dark. I was just hoping someone still running an old school bike had one torn down and could measure some parts for me.

No matter, I'll order a piston in and see for myself what the story is. Either way, I'm going Formula 2 racing next year. The crank work makes me nervous though...
 

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Gossamer has MOJO!!!
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The 99-00 is 20 Thousandths of an inch longer then the 01-05 rods

you may need to deck the block as well depending on how much you de-stroked it your crank.
 

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Discussion Starter #7
Thank you sir. That confirms 1 of the 2 answers I got over at the other board.

I'll still have to mill a good bit off the block, as I'm knocking 2.75 mm (.108") out of the stroke, and I'll have to make up for the lost compression from the smaller displacement.

Maybe I should have just put my kids on the pancake and noodle diet and spent the food budget on an 06.
 

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Curious.. why are you destroking it?

Can you get more power by shortening the stock, but decking the head?
 

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Gossamer has MOJO!!!
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he could get more RPM out of it. and gain some top end power. You have to deck the head if you shorten the rods otherwise the compression ratio would really drop
 

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but you cant raise the rpm w/ the factory ecu... it will still hit the rev limiter regardless of what the engine "can" do, right?
 

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Discussion Starter #11
Well, I think you're both probably right, but that ain't why I'm de-stroking it.

I started looking at the rulebook, and the limit for F2 is 565 cc liquid multis. The class is mainly run with SV's and built FZR's. I started doing the math, and thought my old nail might still run pretty good with 35 less cc's. (If it holds together, I've not heard many good stories about people re-working cranks.)

Anyway, I didn't want to spend a bunch of money on custom rods which would be the right way to do it. There's not alot of material on the front of the cylinders to mill away, and wanted to make up some of the deck height with the taller 01-02 pistons and my 99-00 rods. As it turns out it'll only gain me .5 mm. Still, those pistons are supposed to be lighter, and are coated so I'll try it.

I know it's kinda like throwing good money after bad, but I have alot of spares built up for my old stuff and I hated the thought of throwing it all away and starting over.

Besides, I'm gettin' kinda old to be trying to run with you young guys on 600's, and WERA opened the old man's class up to 1000's. I figured it might be time to try my luck running against some of the lightweight guys. If nothing else, I'm learning about a bunch of stuff I never dealt with playing with 2 strokes all those years.
 

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Gossamer has MOJO!!!
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Thrak said:
but you cant raise the rpm w/ the factory ecu... it will still hit the rev limiter regardless of what the engine "can" do, right?

I assumed he would not use the factory ECU
 

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YamRZ350 said:
Well, I think you're both probably right, but that ain't why I'm de-stroking it.

I started looking at the rulebook, and the limit for F2 is 565 cc liquid multis. The class is mainly run with SV's and built FZR's. I started doing the math, and thought my old nail might still run pretty good with 35 less cc's. (If it holds together, I've not heard many good stories about people re-working cranks.)

Anyway, I didn't want to spend a bunch of money on custom rods which would be the right way to do it. There's not alot of material on the front of the cylinders to mill away, and wanted to make up some of the deck height with the taller 01-02 pistons and my 99-00 rods. As it turns out it'll only gain me .5 mm. Still, those pistons are supposed to be lighter, and are coated so I'll try it.

I know it's kinda like throwing good money after bad, but I have alot of spares built up for my old stuff and I hated the thought of throwing it all away and starting over.

Besides, I'm gettin' kinda old to be trying to run with you young guys on 600's, and WERA opened the old man's class up to 1000's. I figured it might be time to try my luck running against some of the lightweight guys. If nothing else, I'm learning about a bunch of stuff I never dealt with playing with 2 strokes all those years.

yeah the .5 mm or 2 tousandths was obviously to make up the difference in the rods. The wrist pin bore is lower on the 01-05
 

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Discussion Starter #14
For sure I'd need a kit box to raise the rev limit, but I think there is room to play where the power peaks now, and the available revs before the stock box starts killing spark.

What I haven't found an answer for, is the relationship between rod length, stroke and piston speed. I don't know for sure, but I think it's not as easy as saying shorter stroke = more revs = more HP.

Then again, what the hell do I know?
 

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Gossamer has MOJO!!!
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I know an engine builder who could answer all that stuff for you....he is where I got your rod length answer from and all he does is R6 motors. PM me if you want his info.
 

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Discussion Starter #17
KovzR6 said:
ive got the head off my motor im selling as well if you want to help raise compression.

its up on ebay right now. $150 with a new gasket. intake is ported, radius valve job, shaved 25thou.

http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&item=4594368076&ssPageName=ADME:L:LCA:CA:31

.025" seems like an awful lot to take off of the head. Where you using a stock gasket with that set-up? Do you know what compression ratio that turned out to be?

Sorry for all the questions, I've been into these motors a good bit, but have chosen to keep them stock until now. I'll have to re-measure some stuff, but I bet you had to be real careful of your cam timing using that head?
 
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