I have the chance of an rs250 crankshaft which has not been used and looks very similar to the one in my mc16 for a very cheap price.
Will this fit in my bike or am i just barking up the wrong tree.

liam

Its not a easy swap. The RS crank has a shorted taper as it uses a different gen, it also uses a 14mm piston pin (compaired to the NSR's 15mm). This would mean using RS pistons (single ring). This then involves remachining the barrels as the RS pistons are shorter than NSR pistons as well.

Its much easyer just to have the old crank rebuilt.
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If I have to take the carbs off once more...

bugger!!!!!!!!!!!!!!!!!!!!!

I've got a MC18 HRC F3 crank that would fit right on in but you would then have to use F3 pistons so that doesnt help you much. Your gen would fit though!
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If I have to take the carbs off once more...

whats the difference between normal pistons and f3 pistons and how much for the crank?

F3 pistons are single ring (like an RS) and have a 1mm pin offset where the NSR piston is central. Crank price wise, I'm afraid it would be a lot more than what Andy quoted for a rebuilt.

If you already have bearings comming for your old crank I would think it made sence to have it rebuilt and rebuild the engine as it came apart. It will last a good long time if looked after so you wont be in there again for a while.
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If I have to take the carbs off once more...

ok thanks for your honesty
I think i will continue to have mine rebuilt then if it dies again i'll scrap it!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

hi lilblakcooper,
is the crank from 1991 or 92? Do you have a partnumber? If youre not, maybe im intrested in this part for my 92 RS.

regards
Christian
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nsr300se rs250r´05 ns-1rr

Hows about using a hybrid RS250 crank

• swap the alternator end over from MC16 crank
• use MC16 Rods

Just a thought (Im sure someone has thought it before)...
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NSRless again...

StephenRC45 wrote:F3 pistons are single ring (like an RS) and have a 1mm pin offset where the NSR piston is central. Crank price wise, I'm afraid it would be a lot more than what Andy quoted for a rebuilt.

If you already have bearings comming for your old crank I would think it made sence to have it rebuilt and rebuild the engine as it came apart. It will last a good long time if looked after so you wont be in there again for a while.

MC28 pistons and all the MC21's I have seen use a piston with a 1mm offset wristpin. Is that the offset you were referring to?
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Paul Herr
'88 FZR4/GSXR/YZF Frankenbike
MY BIKE PICS

Aren't the RS engines 75degree Vees as well?

This might affect the running of the enine when the spark arrives at the wrong place.....

No,
the RS Engines before 1993 have the same 90degree like the NSRs....
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nsr300se rs250r´05 ns-1rr

drschneider wrote:No,
the RS Engines before 1993 have the same 90degree like the NSRs....

I pre 93 RS engine is an NSR motor

Stephen you tell them .
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