Rotary valve gear stripped 96 XP

[acbprop]

It appears that something fell down into my carbs when I was rebuilding them and jammed the rotary valve. It's not turning. The leading edge of the valve is damaged and the cover has some pretty deep grooves in it. The block has some very minor circular scratches--barely catch your fingernail on it.

So I've got several issues.

I'm hearing that there is a plastic internal gear, and that it's possible to remove the external gear and get to the plastic gear and replace it without pulling the engine. Any comment or instructions?

I understand I'll need to replace the cover and the vane, but are the minor scratches in the block a deal killer? I guess I can have the refaced if I remove the engine, but I'm trying to make this as simple as possible.

If I get to that point, what's it take to re-time the valve? I see some threads about that.

I got this ski for free and have spend a ton of time and a little money replacing all the fuel lines, rebuilding the carbs, replacing all filters, etc. It was running but not well, worse after I did the carbs. Found the valve damage. Good compression both cylinders, ski is in excellent condition otherwise.

Any input on this project would be appreciated.

 

[ski-d00]

unless you're sure you dropped something in the carbs, usually what gets caught in the rv is a needle bearing, broken ring piece, or other internal engine part.

the rv internal gear is brass, not plastic and it can easily be removed with a puller. most likely it's stripped but I suspect other internal damage.

minor scratches in the rv face surfaces are not a big deal, large one are that connect from one port to the other are a big deal.

rv timing is simple, just need to get the mag piston to tdc and use a degree wheel for placement.

Although, it sounds like it's time for an engine teardown to me.

 

[roneagan@cfl.rr.com]

I agee, sounds like the motor went... I had the exact same thing happen to one of my skis last month.. For me it was a needle bearing from one of the rods..

 

[acbprop]

That really does make sense. I don't believe I dropped anything in the carbs--all washers and bolts are accounted for. But how about the good compression? If the motor came apart, wouldn't I see a problem there?

 

[timmyboy76]

where the injection lines connect to the rv cover. Inspect the brass fittingd. Sometimes, they get brittle and fall off, causing the problems you have.