Do any of the NSR250 parts interchange with any Honda ATV parts in the way Yamaha YPVS parts will swap with Banshee parts ?

The point being that I've just found a cool head modification with interchangeable chambers so you can vary the CR to suit.

http://www.prodesignracing.com/images/PD7.jpg

As above...

The ultimate in trick stuff....

Need to win the lottery now...
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These aren't the droids you're looking for.

Can you keep the image size down please?

Ta.

Sounds very cool but surely once you'd found the setup that worked best you'd stick with it? Or is this a variable ratio you can tweak on the move?
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MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball

Well, judging by the number of blow ups and, to be honest, no one really seems to know what's what here - this would be a good way to play and develop a motor. I know the Yam twin inside and out, I know every centimeter of the engines innards and I know exactly what is what and so on but being able to change the chambers represents an option of being able to use your bike in different applications or develop ideas. ie... I can't run my YPVS on pump fuel as it will die, with a cool head all I'd have to do is drain the coolant, pull the head and swap out the chambers. Refit the head (no gasket) and away I go.

People generally don't even know what makes a motor go pop when they run a race ignition with too much advance or the squeeze is way to high for the crap fuel going in so, yes... it's probably a very useful thing for you guys and will continue to be one as long as the bikes keep blowing themselves to bits
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These aren't the droids you're looking for.

Binka...

I'll take the Pepsi challenge any time with that YPVS and my NSR! I bet "a take-away meal of your choice[© Monkey/Fontyyy]" that you will be rebuilding it before I am!

For the last time, they are NOT blowing up all over the place. Without trying to blow my own horn, this is the forum for NSRs, so if there's someone experiencing problems they are most likely to post about it here! With such a high concentration of owners in pretty much just the one place, it's bound to look iffy, but it's not!

Tell me, what is the point of a road bike that won't run on pump fuel? The fuel tank on the YPVS isn't even big enough to get from your garage to the nearest petrol station that sells the stuff! If it is big enough, then great - you can ride to Torquay every time you fancy a ride! A bit limiting just to ride there and back every time you fancy going out though, isn't it?!

It's not like you race it or drag it. So, you spend a million Dollars on a set of heads with inserts just so you can drop the compression back down to a sensible level - why not just have the compression at a sensible level in the first place? Is it really worth that hassle for 1.5hp? What's going to happen on Sunday when there are no 4* gas stations on the ride-out route?
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Andy.
NSR-WORLD.COM

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

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to be honest, no one really seems to know what's what here -

Speak for yourself. I think we have covered the topic QUITE well.
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Paul Herr
'88 FZR4/GSXR/YZF Frankenbike
MY BIKE PICS

There will always be blokes who need to fiddle with their engines - God knows I'm as bad as the next guy - but for a street bike useability has got to be top of the list.

My restricted NSR was damn good fun on the road, so one making 60ish is perfectly good enough when it stays together, does a hundred miles to a tank, and ticks over sweetly at the lights. Much point in trying to find 62hp when you have 60? Not really.

A ripsnorting race bike should have every last ounce of power extracted from it, as reliability isn't quite such an issue, and neither is fuel consumption.

Horses for courses, but as Andy says, I think we've got a disproportionate amount of siezures being talked about right now...
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MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball

Well, Ive never had a single problem with my 250 motor. Its never once let go (apart from when I let go of it at Cadwell lol) and I think I give it some abuse. I run that on bog stock unleaded and she will make 62-63bhp all day everyday. There can't be many flaws in head that can do that from stock?
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If I have to take the carbs off once more...

I think he is on the right lines.

I sell heads with removable inserts (not biased though honest) New business for me.

I would post the link but I don't want to be accused of selling which I am not as they don't fit the NSR.....only RGV.......unless you wanted me to sort that for you?

Arrr what the hell?

www.thetuningworks.com (no stock at mo as all sold out)

Advantages:

Better Cooling
No Gasket
Detonation? Replace cheap insert easy to have det rings fitted or have insert to suit your fuel made. SPecify your own volume/squish etc
Power increase? 5bhp
Fuel? Normal unleaded
How? Better chamber shape

Does not affect jetting, simply burns petrol better and keeps motor cooler (we have seen stage 3'd motors run back down up to 20 degrees cooler into their optimimum range)

If I can get a cheap NSR barrel and find out a bit about compatibitly maybe we could do a head. Turn around time for production could take 6 months and it's not cheap so I'd need to be confident of some orders.

Not everybody wants what come out of the factory, + in our case the design is now 15+ years old. Things move on.
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http://www.rgv250.co.uk
http://www.thetuningworks.com

Heads with interchangeable inserts have been available for the NSR MC21/28 for over 2 years in the UK!

Yeah I know, JHA kits have been around for years etc but that doesn't mean because they look the same they are the same.

Also I was highlighting the advantages, it's definately the way to go.
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http://www.rgv250.co.uk
http://www.thetuningworks.com

Not something I've heard of before, and it sounds interesting.
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MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball