Hi All
My first Post

I have recently purchased a 91 NSR 250 MC21 R, but I dont have a engine for it.
I was thinking about installing a single cylinder 4/ engine, or keeping it a 250cc 2/ and adding perfomance parts.

Any ideas

Thanks
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1991 Honda NSR 250 MC21 R
2010 Yamaha YZF R6 13s
1999 Aprilia RS 154

put an nsr engine back in
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ive seen more tarts than mr kipling

@Silikesguiness

Would the RGV 250 engine fit?, are the horror stories true of this engine?

Admin edit: please read forum rules.
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1991 Honda NSR 250 MC21 R
2010 Yamaha YZF R6 13s
1999 Aprilia RS 154

It can't be that far off, it's a 90* v-twin stroker with the sprocket on the correct side. But no it doesn't "fit".

Stories of power valve woes are all true.
As are stories of terrible, near unusable power curves.
And terrible un-needed complexity.
And needing rocket fuel to make decent power.
Stories of chocolate cranks are not true.
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Please do not PM me technical questions, if you can't find it on the Forum start a thread

Thanks Fontyyy

I guess the stories are untrue then.
I will need to fabricate mounts then to retrofit the RGV 250 engine in the frame?, I have thought about Honda CR 500 engine, but looking at the frame this engine will be to tall.
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1991 Honda NSR 250 MC21 R
2010 Yamaha YZF R6 13s
1999 Aprilia RS 154

Someone did a CR500 conversion, cant remember who. He had bad problems with vibration making in near impossible to ride

Why struggle to fit an RGV engine in?? why not just put an NSR engine in.... I dont understand.... is it a budget or availability issue?

@nobby62

Yeah availability issue, the RGV engines seem to be plentiful and cheap enough; though going on what fontyyy and others have said, sounds like a bad engine choice.

@carbonpaul

I did think about the CR 500, thanks for the heads up.
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1991 Honda NSR 250 MC21 R
2010 Yamaha YZF R6 13s
1999 Aprilia RS 154

NSR motors aren't exactly hard to come by, and even if you adapted the frame "just" to take an MC16 motor with about 50hp, it would still be better than any RGV!

By the time you've messed around sourcing some other motor, ruined the frame forever by modifying it to accept that motor, and then made exhaust pipes, cables, and wiring to suit, it will cost far more than another NSR motor.

If you want an RGV, buy an RGV.

And Fontyyy's quite wrong about the RGV cranks. They're not good either! Maybe one day when he makes the mistake and owns one, he will realise the full truth. The tolerances are nowhere near that of the Honda motors.
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Andy.
NSR-WORLD.COM

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@Andy
Thanks for the advice.

Any Ideas on sourcing such an engine.
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1991 Honda NSR 250 MC21 R
2010 Yamaha YZF R6 13s
1999 Aprilia RS 154

I've got a 2010 KLR650 engine to put in mine. Estimated completion date tentitives set around the 30's based on current progress.

RD350 would be my choice if it wasn't an Nsr engine.

I wonder how an NSR250 engine would go in an RD350 chassis?

why would you do that my rgv was a nightmare,mine and my mates did the usual powervalve failure,mark sold his before his rgv motor shat itself
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ive seen more tarts than mr kipling

Dannyvirk wrote:
I wonder how an NSR250 engine would go in an RD350 chassis?

This was on Yahoo! Auctions recently.

Watfordhorn wrote:
RD350 would be my choice if it wasn't an Nsr engine.

As Leigh already knows, Martin77's already successfully done this:

"

NSR-D350SP!
_________________
Andy.
NSR-WORLD.COM

Please keep all responses to Forum posts on the Forum so that others may benefit.

Please DO NOT PM me for technical advice. My time is precious, and you will probably receive a faster response on the Forum anyway.

Check us out on Facebook! Please "like" our page!