Hey guys (and gals)...I'm having a bit of a problem getting my JS550 to run properly.
The ski has been sitting in a garage for a few years. Everything seems to be well taken care of. The head had been milled and compression is right at ~150 in both cylinders. I bought a new battery and a fresh set of plugs, emptied and cleaned the tank and refilled with fresh mix and away I went.
Problem #1
I can get the ski to fire up but it's a rough start. It doesn't fire right up like my brothers 650. I have to primer it and lay on the throttle for a few seconds before it will fire up. Once started I have to feather the throttle to keep it running. It will not idle at all. I've tried adjusting the pilot and idle adjuster with no luck.
Problem #2
I haven't had the ski under load yet - just hooked up to a hose while trying to make some carb adjustments. After the ski has warmed up - sometimes I punch the throttle to hit a higher RPM and it will 'runaway'. Basically I have to prime it and flood it out for it to stop running. Pulling the plug wires won't stop it.
I've read around a bit and it looks like crank seals are the most common culprit. However, I pulled the front flywheel cover and everything looks fine. I felt around on the rear seal and it doesn't seem to be bad either. Obviously a leak down test would tell me for sure but I'm not quite sure how to do that.
Also - I rebuilt the carb and replaced all gaskets on the intake side just in case there was an air leak somewhere. Obviously the ski is running lean but I'm just not sure from what. I'm thinking my high mixture screw is set too lean because it only wants to run away when I hit WOT.
Thoughts/suggestions?
The ski has been sitting in a garage for a few years. Everything seems to be well taken care of. The head had been milled and compression is right at ~150 in both cylinders. I bought a new battery and a fresh set of plugs, emptied and cleaned the tank and refilled with fresh mix and away I went.
Problem #1
I can get the ski to fire up but it's a rough start. It doesn't fire right up like my brothers 650. I have to primer it and lay on the throttle for a few seconds before it will fire up. Once started I have to feather the throttle to keep it running. It will not idle at all. I've tried adjusting the pilot and idle adjuster with no luck.
Problem #2
I haven't had the ski under load yet - just hooked up to a hose while trying to make some carb adjustments. After the ski has warmed up - sometimes I punch the throttle to hit a higher RPM and it will 'runaway'. Basically I have to prime it and flood it out for it to stop running. Pulling the plug wires won't stop it.
I've read around a bit and it looks like crank seals are the most common culprit. However, I pulled the front flywheel cover and everything looks fine. I felt around on the rear seal and it doesn't seem to be bad either. Obviously a leak down test would tell me for sure but I'm not quite sure how to do that.
Also - I rebuilt the carb and replaced all gaskets on the intake side just in case there was an air leak somewhere. Obviously the ski is running lean but I'm just not sure from what. I'm thinking my high mixture screw is set too lean because it only wants to run away when I hit WOT.
Thoughts/suggestions?
Comment