well, had the compression checked today.....205 psi! Need to run 105 or 108 racing gas now, great[img]i/expressions/face-icon-small-mad.gif[/img]. A certain individual relayed to me that i will probally burn a whole in top of the piston real soon (and i am thankful for their advice),

does anybody know what the compression ratio would be? like 11:1or 10.5:1 and so on. I would lik to know. well wish me luck on keepin my quad running...I'll need it. AAEN performance offers a 300 motor mod for this bike...i'll have to put this on when i burn up the old one[img]i/expressions/face-icon-small-wink.gif[/img]

 

205 psi cyl pressure is on the edge of extreme....like 14 or 15 to 1. I would try another guage for a "second opinion".

 

I had an old KTM dirt bike, if I remember ... the base gaskets on the bottom of the cylinder had a lot to do with the compression..the deck height was pretty critical..& was measured from the top of the cylinder bore to the top of the ring at TDC..I rember shimming a lot of gaskets to get it right..I think it had about 185 lbs or so..premium gas was ok..but you might want to check....this WAS 25 years ago.& it was a 2 wheeler.

 

205 might be to much that is the comp. I was running right before the cylindr lifted and cracked the cases. That was on a 400 dont know about the 250.

 

Check the comp gauge. At 205 psi you will have a one-race wonder. That is pretty extreme.