compression/gas ?

[gasmask2008]

i have a 1985 honda 250r 3 wheeler with a 295 big bore kit[bored 1 time over],esr aftermarket cylinder head with a 18cc dome,38 mm carb with a power jet,rad valve and reed spacer plate,the atc head gasket and a 1992 cr 250 complete ignition system...what's the higest compression i can run with pump gas?

[350XXX]

10.5:1. 11:1 or higher and you need 110 octane or higher.

[Oldschoolin86]

Originally posted by 350XXX
10.5:1. 11:1 or higher and you need 110 octane or higher. WHAT? 10.5:1 - 11:1 shouldn't need more then 93-95 octain and that's IF it's an air cooled motor. A liquid would handle that on pump gas with ease. Besides all that, a 2-stroke isn't rated like that anyway so those numbers aren't that helpful. Usualy the MAX you can get away with on 93 is 180psi. After that your gonna have to start bumping up the octain.

[my90rulz]

Im supposed to be able to get away with 200psi on pump with meh PV Z....:confused:

[350XXX]

Originally posted by Oldschoolin86
WHAT? 10.5:1 - 11:1 shouldn't need more then 93-95 octain and that's IF it's an air cooled motor.

then you argue with the pro's. here is the link, scroll down the page until you get to the last big bore kit and read the requirements.

tech page (http://www.powroll.com/P_HONDA_ATC350X.htm)

[no_doz]

i know people that run 93 pump gas on 11:1, thats pushing it though, to be safe you should go with higher (thats why it says to go higher, so someone doesnt use 93 with 11:1, get lucky and mess their motor up, then come back and sue powroll or put down their products reducing sales).

[bones200x]

When a company RECOMMENDS something...It usually means it has been tested. It may run on 93, But in order to get the "total" performance, You should run 110. Too little of octane creates spark knock. Which is like being lean and will burn a piston.
On the other hand. If it said NEEDS!!! Don't take short cuts.
My 200x has around 11:1 ... I run 93. I cant say I shouldn't run 110. I can tell a difference between mine and my friends on a real hot day. He runs Cam2 (112). I can't afford to run that that much. right at $5 a gallon. It takes $6-7 dollars to fill up on 93..lol(depends on where I buy it)

[ridetrikes250R]

okay 10.5-11:1 can be run on as little as 91 octane... but on a twostroke you dont go by those numbers... you should be able to run 180-210 on pump gas but 210 is pretty high on 93 i have run motors up to 195 on 91 and never had a problem i mixed it 32:1 tho just to be safe...
adam

[Oldschoolin86]

Originally posted by 350XXX


then you argue with the pro's. here is the link, scroll down the page until you get to the last big bore kit and read the requirements.

tech page (http://www.powroll.com/P_HONDA_ATC350X.htm) Build a few motors and see what works instead of reading about it and you'll know. ;)

[no_doz]

exactly, lol