Hope someone can help! This has happened twice. Kawasaki 1100 STX DI - 2000 approx. 70 hours run time. First, melted exhaust resonator (plastic ball with inlet and outlet between muffler and exhaust outlet); replaced it. Next burnt hole through hose between exhaust manifold and muffler; replaced with hose from tractor shop (heavy duty rubber hose); burnt immediately through that; replaced with hose from aftermarket dealer. Now has melted resonator again. Each problem has occured on first time out after parts were replaced and within 30 minutes of run time. There is a steady stream of water flow from the side tattletail (for lack of a better word). Engine does not seem to be over heating and no warning lights come on. Any ideas on what could be causing this problem?

PS Removed hose connecting from lower rear of jetski to rear of engine and blew through it, dosen't seem to be clogged.

 

Welcome to the forums....

You have checked everything that I would have thought of.....

I bet someone with more ski experience will jump on here

GL man...

 

On the front of the motor down by the oil pump you should see two 1/4in black hoses that attach to a cover that is held on by 5 or so 10mm bolts. take that cover off (just the small thin one not the whole stator cover) and see if there is anything plugging the passageway, if ther is drill out the fittings and clean out the passageway. those 2 hoses run cold water around the stator to cool it the water then goes to the exhaust to cool that when these get pluged it will start to burn the exhaust hoses eventho the motor is not running hot

 

thanx for the reply guys (kawman and br18w)!!

Kawman, took off cover as suggested; hoses clear, no clogs. water runs through freely. someone at a local automotive shop (says he's familiar with 2cycle engines) said fuel running to lean will cause overheating (told him no carb on ski); is this possible? if so, how do you adjust fuel injection; i didn't think thats possible. any ideas?? is it possible something could be clogging injection system? would it be ok to run injection cleaner as you would in a car?

edit: removed exhaust pipe, checked all hoses and passages; air flows through easily dosent seem to be clogged. same with water flow through all passages.

 

what color are your spark plugs. they should be a light brown after hard use. if it was running lean enough to melt the exhaust boots the motor should have melted down a long time ago. i would lean to a cooling system problem. check all of the hoses you can find. there should be one that goes thru the ecm also. if any one of these get plugged or even just restricted it can cause huge problems. as far as the fuel injector cleaner i would not use any.

 

Hello 1100 D.I.,
Don't listen to the auto shop guy.... You exhaust system ONLY is overheating, not the complete engine. If it is too lean of F/A ratio, it would hole the pistons first. Some place in the cooling passage in the exhaust system is clogged up by debris like sand, trash, small pebble/shell pices, or whatever. Your job is to find where - most likely at one of the brass 90-deg fittings. Remove each fitting and make sure you can see through. Or it even could be the hole at the exhaust manifold/pipe that's clogged up. Find where it is clogged up first. As you realized, putting in new parts on the overheating exhaust system only will burn them again and again. Try flushing and blowing with high psi air to clean out the clogging.