250R Compression

[Fox250R]

My R has 190 psi......Is this too much or not enough? And how much compression does a stock 85-86 250R have?

[lisnup65]

190 is actually high. It requires the use of preminum fuel and is on the verge of needing a even higher octane. My 85 250R has 145psi.

[deathman53]

a stock 250r has about 180 on a atc gasket and about 165 on trx gasket, my atc was running 220 psi and that is with a atc gasket, I never put a cr gasket in. Most cr gasket motors with a coolhead and 18cc dome run at 250 psi. I use race gas, so its no big deal. If you want, get a 89 head, its cut thicker as honda lowered the compression for the 89 year(in 88 people apparently were having problems starting the bikes, becuase of the compression), each year head has a different dome and different compression. I think the atc's had the most, then the quads got less and in 89 it dropped more.

[Fox250R]

cool thanks for the info...

[md1985250r]

Stock engine 85R........170.7-199.1 psi is factory spec on compression. GREG



ps...lisnup..you need some work done my friend.Good luck

[Fox250R]

so i guess 190 is pretty close then...Cool,Thanks for the info guys... :)