Has anybody checked their compression? What is the spec. for good rings (psi)?

I am going to check mine tonight. I have put 2 hard years on my stock motor. I have raced MX a little and I did alot of drag racing at Silver Lake. I have decent low-end power, but I lost my top-end. I susepect my motor is getting old. When I adjusted the valves, it was easy to turn over with the wrench. The head gasket is fine, it does burn a small amount of oil.

 

does it smoke? you may have blown a head gasket. I maybe wrong but I think anything over about 120 psi is good, but I'm just guessing here. maybe someone else will have the info you need. Good Luck [img]i/expressions/face-icon-small-wink.gif[/img]

 

100-128 psi is acceptable

 

Does anybody know the spec?

100-128psi is only acceptable for 2 strokes.

I measured mine yesterday and got 165psi! This is a good number. I heard new is like 175?????
After I was done, I calibrated my tester at work, it is only off by 1 psi.

This weeekend I will get the chance to test an '03 with like 10 hours on it. I will report the results.

 

I can't find it in the Honda sevice manual. good luck with your ride this weekend.

 

page 5 (x) of my shop manual states "cylinder compression: 100-128 psi ( 686-883 kPa)

 

I found it in the honda sevice manual on page 7-1 and it says the same thing you did"cylinder compression: 100-128 psi ( 686-883 kPa)

 

I would rebuild it if you had been using it for MX, chances are it's due for a fresh topend.