97 Sea Doo GTX

[freddyzp]

I have a 97 GTX with 200 hrs on the hull. I am on my second SBT engine. My current problem started like this...

While riding the speed would bleed off with the RPM's constant
The engine would backfire and would die
After a few min I could start the craft and bring it back to the dock.

I checked the plugs. They seemed ok but decided to change them.
I let my kids take the craft out and the same thing.. I checked the plugs again they looked wet but ok.. I took it out and it seemed ok then it happend just like I stated previous No matter how much gas I would give it the RPM's would bleed off and it would only go about 20 mph.. I called it a day (not happy). I had never changed the fuel filter so I went to the local Sea Doo dealership ath the Lake of the Ozarks and picked up a new filter element. The one installed was dirty.. Problem solved NOT It would run but would backfire when running. I consider myself somewhat mechanical savy, I replaced my first SBT my self and am an aircraft electronic mechanic for the military. This was killing me. I could not figure out what was making it backfire. I know the timing has a lot to do with it. I broke the engine down to the carbs and looked to see if anything obvious. will continue

[Technical Support]

Re: 97 Sea Doo GTX

Lack of spped with normal RPM is always a driveline/pump problem. Most likely you need an impeller and wear ring to correct the cause of your problem. Engine wise, you overheated it and it needs ot be replaced again. The pump provides the cooling water. When you have pump cavitation you don't get enough cooling flow. The engines don't die/stall/shut off. They sieze. Everytime they do, it does engine damage.

[freddyzp]

97 Sea Doo GTX

Ok changed plugs no help. Changed fuel filter no help. Then it just would not start it would crank and try but no fire. After 91 dollars I replaced the coil I could not see a spark. Gotta be the coil right NOT. Finally I reached the point and took my boat to OZARK powersports, they were recommended by a local marina. The guy was great checked the compression it was good on each cyl. He said to leave it with him and he would give it the once over. Two hours later and 87 dollars more he told me the only thing he could get it to do was backfire and shoot flames out of the carbs. I gave up and the boat sat on the trailer for the rest of my vacation. I dug into the engine down to the rotary valve to check the timing of the rotary valve. I also had access to an engine borescope to check inside the cyl and inside past the rotary valve. it all looked good the pistons have no chips the inside looks ok no metal shavings I can even see down to the oil inside. I am at the end of my rope. I need some advice. HELP
I am willing to take it to the shop but dont really want to.. but I will if that is the last hope. I dont want to put a thousand dollars into my boat. Any help or ideas would be appreciated. Thanks

[Technical Support]

Re: 97 Sea Doo GTX

Don't start new threads for a reply. I'm merging your threads.

[Technical Support]

Re: 97 Sea Doo GTX

What you said makes no sense. If you have charge coming out your intake, the timing is not correct, period. The brass gear has at least partially stripped. The engine needs to be replaced.

[callowaygroup]

Re: 97 Sea Doo GTX

I agree, it sounds like timing. or maybe you put you spark plug wires on backwards J/K

[dsolie]

Re: 97 Sea Doo GTX

Wouldn't matter.

I agree, it sounds like timing. or maybe you put you spark plug wires on backwards J/K

[callowaygroup]

Re: 97 Sea Doo GTX

Wouldn't matter.

I've been fixing cars in dealers since highschool and have plenty of certification-most recent was the ASE L1(advance engine performance specialist). I'm failry new to the jet world of repair but I haven't come across any engines where wireing the spark plugs the correct way doesn't matter. Could you explain this to me?

[dsolie]

Re: 97 Sea Doo GTX

On that ski it only has a single coil, there is no alternating sparks. On some ski's there are dual coils that spark independently

[callowaygroup]

Re: 97 Sea Doo GTX

I have a 97 GTX that I'm in the process on reconditioning. I'll have to dig into the cdi box and check that out. Thanks for the knowledge.:beer

[dsolie]

Re: 97 Sea Doo GTX

Yhea, just like another post on this site said recently.. Is not as easy as a car's distrubutor.. But, the coil / exciter and trigger is about as simple as can be. A lot less parts to have to trouble shoot.

When you look at the coil, see if you have two white wire inputs (triggers). If you do, then it's a dual wire coil and can spark independantly, if it has one, it's a single sparker.