What is the compresion on a good motor. I want to check it due to my sons LT80 sitting for two weeks and all of the gas filled the cylinder and some how filled the shroud that covers the engine. It kind of sucks i just bought the vacuum petcock less than three months ago so i ordered a nother new one this time one that does not have the vacuum port just a on and off. I am just worried that there is a gasket that is bad on the engine. the bike was a little low on power i thought and i never heard the sam sound on my other 2 stroke bikes when the power band come in. So i think i may tear into the engine and put a new set of reeds on it and do some performance work.

 

Compression really ranges from bike to bike and from if it has aftermarket parts or stock but stock compression usually ranges from around 115 to 130 should be ideal. Anything less than 100 psi of compression is a sign for time for rebuild.

 

thanks for the quick response the bike is completly stock i was just looking for a range of what i might see since i have to wait for my next day off to do some work on it.

 

90 minimum.

 

thank you for the information I was also wondering if the reeds are bad will this give a lower than normal compression.

 

Bad reeds won't bother compression in the cylinder because compression happens after intake but if you have a bad or broke reef you won't get the right fuel air mixture to your motor.

 

Finally felt good enough after sugary to get up and do something so I tested the compression it was 108 so i guess I dont need to rebuild the engine. I just need to swap out the brand new petcock for the none vacuum type and try to run it again. The bike just seems like it should of had more power than what it did hopefully lt80 might be able to help out there.

 

Well I got the petcock swapped out and after letting the motor air out for few hours I tried to start it but had no luck it just cranked so I eaither need to let it air out more wich is what I think will need to be done or something else.