Did a compression check on my 02 Viper. PTO side was 110 other 2 were 125. What is stock on these things ? I'm running an opticool head gasket and bender pipes. It's been a few years but it seem like the center cyl was less than the otheres until adding the opti - can't remember. Should I consider slapping a new set of rings on all 3 or is 110 acceptable for a sled with 4400 miles on it ? What to do ????
It seems to run good. Just trying to stay ahead of a major problem.
It seems to run good. Just trying to stay ahead of a major problem.
Those are the stock compression numbers. Yamaha dropped the compression on the PTO side so they could run the same jetting in all 3 cyl. To get the maximum life out of a 2 stroke i have been told to replace the rings every 3000 miles.
Eric
Eric
Thanks Eric. I thought one of the 3 was lower than the others but couldn't remember which one it was. With those being the stock numbers I feel a lot better about the motor.
Why is it that the PTO cyl has to be lower compression to run the same jets ??
Why is it that the PTO cyl has to be lower compression to run the same jets ??
If you ran even compression in all 3 cyl with the single pipe the heat from the clutch would cause the PTO side to run hotter. Yamaha dropped the compression to reduce the heat instead of running a bigger jet. They wanted to simplify the jetting. Why? Don't know.
Eric
Eric