Which Rotary Valve do I need!?

[SquirrlyDan]

I recently picked up a non running 94 XP with a 657X. The motor was toast, and the guy i bought it from gave me an extra engine that he was under the impression was a good engine, i went ahead and threw a new top end kit in the new engine before putting it in the ski. The original engine that was in the ski(blown up engine) had a 5 wire stator. The new engine had a 4 wire stator. I swapped the stator and flywheel(5 wire) out of my blown up engine, into the the new engine going into the ski. Skip forward and got the engine in and hooked up. The engine runs, but is hard to get it to come off of idle, bogs when you try to rev it and such, seems to kind of rpm search as well. From my understanding based off what ive read, that i had to swap the flywheel and stator because the timing is different on the flywheels from the 5 wire to 4 wire stator systems, but I did not change the rotary valve.

1. Is the rotary valve different from the 657x with a 4 wire stator to a 657X with 3 wire stator?
2. I know that the open and close degree spec is different from a 657 to a 657X, but is the spec different from a 657X with 4 wire stator, to a 657x with a 5 wire stator?
Thank you guys in advance for any help, im completely at a loss and the more post i read about it, the more confused i get.

 

[NickCawks]

Sounds to me that your ignition timing is off rather than the rotary valve.

I am not exactly sure about your question but the manual specifies on the rotary valve on 03-06. Maybe pull both rotary valves out and see if they are different angles?

07-05 speaks on the magneto and ignition. It appears that there were two options that came in this year. the double coil system (5 wires) and the single coil system (4 wires)

It speaks on adjusting the ignition timing on 07-02. Here you will see that there are different angles for different models of skis. I believe the XP was the only one that came with the double coil system. However, there are three potential angles to set the ignition timing on.

not sure if any of this will be helpful to you. This is something I have never dealt with before so I am purely speculating. However, it sounds to me that maybe you just have the ignition timing set for the wrong motor.

Hopefully, someone with more intimate knowledge on the difference between these ignition systems will pop in with some clarification soon.

 

[SquirrlyDan]

Thanks for the response! I did end up taking the the rotary valve out of both old and new engines to compare them, The weird thing is, one measures at 159 degrees, and the other is at about 157. So i guess they are both 159 valves, but maybe one is aftermarket so is a little off. I have ordered a new valve and am going to throw a new one in just in case, also, when i pulled it apart i double checked the rotary valve timing and opening was at about 139-140 degrees, i understand that its suppose to be 149 +/-5 degrees. Do you think that being 9-10 degrees off from 149 spec will cause such issues?

When i installed the stator onto this engine, I'm positive that i lined the timing marks up perfectly, so i don't think that it would be out of ignition time, "think" being the key word.

 

[mikidymac]

You can flip the rotary valve over to get it closer as they are actually eccentric.