airtime

Hi, have a 99 XL760 that has been running solid for me the last 4 times I took it out. However today, it died on my while riding in the middle of the lake. Had to wait about 1/2 before I drifted close enough to shore to get off and tie it down and walk back.

Right before it died, I felt a loss in power and it slowly revved down before shutting off. All it does now when I press the start button is a single loud thud which I guess may be the starter? It never turns over now I've ruled out the battery, but what else can this be?

Anyone??

Thanks in advance.

pwc-abuser

You may have siezed the motor.
Take the plugs out. At the rear of the motor is a shield that covers where the PTO meats the drive shaft, remove this is should be easy. With the plugs off, you should be able to rotate the crank easily by hand. with plugs off the starter should spin the motor easily.

If not, you have one of 2 places you can start to look. You can remove the nozzle, then the pump duct and pull out the drive shaft and impeller, it should pull straight out. Try to rotate the motor now. If it rotates easily, then you could have swelled up and siezed the pump housing, which is much easier to fix. If however you press the start and it still thumps, then the motor is probably bad.

Or, you could just start by taking off the head. New head gasket is probably only about $50 at worst and the head is easy to replace. You might see damage there.

Start with checking the easy stuff first....

airtime

Hi pwc-abuser,

I followed your advise and took the shield to spin the shaft. We'll it spins up to a point then goes "thunk", I can then spin it back the other direction. I took the cover off to see the pistons. Looks like problem with the piston toward the back of boat as it seems like the linkage or something is disconnected. The piston towards the front will go up and down.

I need to know what else I need to unbolt to get below the piston. Do I need to unbolt the Blue color whatever that thing is at the top of the picture? Is what I'm describing replaceable without replacing the whole engine? Thanks in advance. Dave.

sandman7793

Might as well go ahead and pull that engine. But if you just want to look further pull the exhaust ( blue thing as u call it ) and then you should see the bolts around the base of the jugs ( things pistons are in ). You either broke the bottom of the piston out or snapped a connecting rod or broke the crank

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ZMANN

Agreed ! plus it looks like the rear was running lean .. but you may have dropped an oil line to that cyl ,, either way pull it and go for a complete tear down

engine removal and carb rebuild link http://shopsbt.com/guides.htm

and go thru the carbs while your at it

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