657x rotary valve

[norris3710]

I have a seadoo speedster and i just got a new motor, I have the shop manual and it says that i need a 158 deg rotary valve the only problem is they dont make a 158 they have a 159,will that work?

[Bill O'Neal2]

Re: 657x rotary valve

Yes a 159 degree duration Rotary Valve will work in the 657X motor. It comes standard in 657X, 718 and 787 engines.

[norris3710]

Re: 657x rotary valve

another question what are the pros and cons of carbon fiber and the steel rotary valves

[Bill O'Neal2]

Re: 657x rotary valve

Carbon fiber RV's are junk. The oem RV is as good as it gets for RV's. They outlast all others and they do not flex and eat aluminum off of the RV surface of the cases.