Quote:
The end valves for crankcase are supposed to be air pressure released @ 4.60 lbs, AIR PRESSURE.
The Yamaha valves I use are from triple two stroke snowmobiles (and other 2T applications) and crack at 3psi. They also have rubber seats and a plunger stop which prevents spring distortion. Oil consumption is the same as a typical H1 or H2 so in that case I suspect the extra pressure rating may have helped the old brass valves seal better being something Kawasaki discovered during production. I configured the my first back in 2017 and it's still running well with normal oil consumption and no leakage. If a valve ever goes south it is easily replaced. Many others have had the same results, being totally fed up tinkering with junk. Being less dated they would be better suited to newer oils one would reason, which is what we have available these days. Suzuki and Yamaha guys use them too being that they are generally intended for 2T engines, that's where I found them lol.