Really Stumped

[broncoking]

I've done my fair share of motor rebuilds but I have a 97 XP w/ 787 that is baffling me.

I bought the ski 2 years and have never heard it run. The buyer assured me all I needed to do was bolt the carbs back on and it would run...:banghead:
Fastforward to today...Ski has been sitting for 2 years...and still won't start. Cranks over fine and has spark.

Here's what I have done:
2) Compression was REALLY low (50 psi per cylinder) I thought it had ~150 PSI ea last time I looked at it (granted that was 2 years ago.)
3) Reset the Rotary Valve thinking it couldn't the cylinders
3) Removed Head... Cylinders and Pistons look great!
4) Reassembled with new O-rings and read ~ 50 PSI again...

So I am not sure what else it could be?
Can the RAVE valves cause low compression if something is wrong with them?
Maybe my rings are stuck around piston and not sealing...

Any ideas.. Please help.

Thanks

 

[timmyboy76]

thibk you found ur problem, stud...50psi. Try again, make sure throttle is open.

When you installed the RV, was the "pto" port hole, closed off, if not, then "that" is 180* off,

 

[SRUSH]

put a little oil in the spark plug holes and do comp test again if compression comes up it could have a sticking ring. ive heard you can pour some trans fluid in there and let it soak and the detergents in there will free the ring up

 

[broncoking]

timmyboy76 - I used my SD Service manual to set the RV valve...so I honestly cannot remember - but I think the PTO side was closed...

Last compression check I did was without the carbs installed - I assumed that's an OK way to check?

I have not tried the oil trick yet..

 

[broncoking]

Update:
Was stuck rings - pulled the cylinder and rings were very stuck - fresh rings and the compression is great again.

Hoping to reinstall tonight and see if I still have a pesky ignition problem that I remember having before I let it sit....

Thanks everyone.:cheers: