yz125 compression...

[tyler_43]

Did a compression test on my 2002 yz125
first compression test cold (6 degrees outside... in that weird temperature you southerners use it's 43) and got 136 (I hadn't run the bike in 2 weeks so maybe there wasn't much enough gas around to provide a good seal?)

second test i fired up the bike just until the rads started getting warm... shut it off, let it cool down for 10 mins, and then tested it. I got 150 that time...


does that sound bad? I've heard 160-170 from different people...

 

[BigRedAF]

That's a bit low for a warm bike. The current crop of two stroke power valve bikes generally put out around 185 psi. Don't be worried, a new ring or piston and ring set will most likely solve your issues.

 

[Ron2stroke1]

I ran my yz125 till it dropped to 105 psi and it still ran great. Started right up, and had alot of power.

 

[BigRedAF]

I ran my yz125 till it dropped to 105 psi and it still ran great. Started right up, and had alot of power.

Runs great is a relative term, compared to what?