'85 250r head

[moomba010]

I was looking at swapping my stock head out for a "cool head"... I was unsure however about size... Is there a measurement or is it preference.....? Also if using that head... Ay recomendations on carb sizes?


Excuse me if these seem like novice questions... I am new to this...

[atc300r]

Its mostly prefference.

[moomba010]

Is one more beneficial than the other.. I.e. A 21cc gives you more than a 19cc?

[RIDE-RED 250r]

19cc would be higher compression ratio than the 21cc and would require race fuel. I'm not sure where the line is for dome cc that puts you into race fuel territory... usually anything above about 200psi compression gets your minimum octane requirements above pump fuel....

[moomba010]

Thanks... that helps a lot! :-)

[moomba010]

So if I were to get a 21cc dome with the cool head... Any suggestions on a carb to go with...

Also, I want to stay with reg fuel...

[RIDE-RED 250r]

This right here is a great carb upgrade and reasonably priced too. I'm running one on my 350BB.. http://www.eddie-sanders-racing.com/product_p/38mm%20airstryker%20keihin%20carbs.htm