Will not run in the water?

[X-Runner]

I have a 94 Monte Carlo (bought as a non running project). I cleaned the entire fuel system and the ski runs perfect on the trailer. Starts at the touch of the button and idles, revs etc flawlessly. Compression is 135 PSI in both cylinders. The ski will not start in the water (has a primer and it wont fire with it either). I can start the ski on the trailer, slowly back into the water and it goes dead. Ideas?

[landonm11]

compression seems a lil low...

640s run about 150+

145 is okay but i wouldnt do anything lower

[X-Runner]

135 seems like enough to run to me. My 650sx had 120 in both and ran strong. That reading was with the same gauge.

[Swiss]

Plenty of comp my $ is on a bad head/gasket.

[X-Runner]

Can you explain how a bad head gasket/head will cause this? I pulled the plugs when it stalled in the water and the cylinders were dry. No water.

[X-Runner]

Okay, played with it some more today. Got it to run and took it out in the cove for 3-4 minutes. Then it stalled out. Checked compression (same gauge) and it came up to 140 on both. Plugged the plugs and the MAG cylinder is extremely lean and the PTO was wet with fuel. This makes no since to me as it is a single carb engine? I did verify that both plugs are firing and they are new.

[landonm11]

Cut the plug wires back about half an inch and then make sure you put them on the right cylinder

Sounds like your not gettin enough spark in the pto cylinder

[X-Runner]

Cut the plug wires back about half an inch and then make sure you put them on the right cylinder

Sounds like your not gettin enough spark in the pto cylinder

Already did on both while at the lake today. No change.

[Swiss]

I would pull the motor and tear it down before you do major damage. You can get a complete gasket kit for the 640 from PWC engine and it includes new wrist pin bearings for just $70.

It could be a reed not closing or a hole in the bottom of the case even. Until you pull it and leak test it you will never know.