roudyroy1
Active member
i know that the pto cylinder has lower compression than the other 2, but what is the theory behind this? any one shed some light?
pto cylinder compression
- Thread starter roudyroy1
- Start date
super1c
Super Moderator
Instead of running staggered jetting like the srx , on the viper they run straight jetting and lowered the comp on the PTO. All about cooling. Larger jets better piston cooling, lower comp less heat. This was a poor design by Yamaha hence all the cooling issues on the vipers.
roudyroy1
Active member
hmmmm, interesting. so what makes the pto cylinder get so hot? just bad coolant circulation?
super1c
Super Moderator
http://www.totallyamaha.net/forums/...2&pp=10&highlight=staggered+viper+compression
Post # 12,14 by mrviper does a awesome job of explaining the staggered compression.
Post # 12,14 by mrviper does a awesome job of explaining the staggered compression.
mile9c1
New member
My Yamaha Waverunner runs lower compression on the PTO side, and supposedly the ignition timing is retarded too. I think the PTO side just sees a higher load, hence it needs more babying. Better cooling, bigger jets, less timing - these are all bandaids.