[jerechrist1234]

I have a 1996 Tigershark Monte Carlo 900 that spontaneously overheated last year. When it overheats, it must have a temp sensor and kill the jetski. If you let it cool down for a while, it would start back up and run for a little bit until it would overheat again. We thought it might be a clog in the cooling system, so we flushed the cooling channels as best we could without taking apart the whole engine. That didn't help.
I think at one point the impeller shaft seized up, so we went through that end and replaced the floating bearing (I just know for sure I replaced that stupid bearing).
Fast forward to now, we have spark, we have gas getting to the carbs, but it won't ever fire. We can put gas or starting fluid straight into the cylinder and it will not fire.
I am wondering what ideas anyone has that this could be?
I think it is down to a timing issue. Which could be caused by a bent or partially sheared flywheel key?
I don't know how something gradually falls out of timing, but if a flywheel key got bent, it could still run, but with symptoms gradually getting worse?

 

[Greasemonkey]

I’m attaching a pic to show you through the hole located on top of magneto housing what flywheel should look like with arrow on magneto cover inside pointing to a scribe mark and a T stamped into flywheel when #1 (mag) cylinder is topdead center or that piston closest to magneto is as high up as it goes that would indicate it is in time.

 

[jerechrist1234]

Mine was no where near in time. So it would spark and the fuel pump would work. You could put gas in the cylinder or even starting fluid and no bang at all. I popped off the flywheel and the key was sheared. Put in a new one, and after a year of chasing problems, she runs like a top again.

 

[Greasemonkey]

I always like to hear back on the progress. Have fun unleashing the “beast!”

 

[Greasemonkey]

Before i forget, the temp. sensor you mentioned in 1st post is on the outside bend of exhaust between exhaust manifold and expansion chamber closest part to fuel tank. There must be dielectric grease which you can get at auto stores. I dab a little on face of sensor after removing the phillips screw . So theres dielectric grease between sensor and exhaust pipe. If needbe you can use a thin wire or straightened small paperclip between sensor and pipe to “bleed the air out” to get it reseated properly again. I use dielectric grease on all electrical connections. Keeps them waterproof and unrusting, even on sparkplugs and boots etc.

 

[Greasemonkey]

A must for all my jetski’s