96 GTX runs for a bit then dies and won't start

[Mattytrucks]

I have a 96 gtx with the 787 motor. It starts up. Rpms over 4000 are intermittent then it will shut off and not start back up. The problem started last year. I had a local guy helping me figure it out and he helped me spend a bunch of money. The electrical box was swapped out (ecm, cdi). new stator and pick up. replaced the coil. What else could it be? There is no spark. after sitting over night it will start back up and do the same thing. Any ideas would be greatly appreciated.

 

[Ckrawiec]

I'm confused....you state "there is no spark"...BUT the ski starts? There has to be some spark for the ski to at least start.....no fire, no start.
I have the same ski and I've been through it pretty thoroughly.....first off.....stop throwing money at it. Cheap things first.
First things first....you do not mention any work on the carbs...has anything been done to them? Does the ski still have grey tempo fuel lines or black automotive fuel lines?

 

[Mattytrucks]

carbs have been done. it is getting fuel. of course there is spark in order for it to start. there is no spark after it dies when trying to restart.

 

[Ckrawiec]

HOW were the carbs done? MIKUNI carb kits (OEM) or OTHER?

I did mine with carb kits from SBT....no dice. Ski would start and run great on the trailer, would not perform on the water though....bogged down immediately with throttle. Switched back to original Mikuni carb kits....MUCH JOY!

Ignition coil replaced? Sounds strange that you would have enough spark to start then lose spark all of a sudden. The '96 uses a wasted spark system so BOTH plugs fire simultaneously...I would think you either have spark or you don't....but you indicate that this is exactly what you have.

The spark signal comes into the ignition coil (in the rear electric box) on the WHITE wire. I'd be checking (tracing wires) for continuity, good grounds, corrosion.....if you definitively rule out the carbs...then you have an electrical gremlin....always fun to chase them.

 

[Mattytrucks]

HOW were the carbs done? MIKUNI carb kits (OEM) or OTHER?

I did mine with carb kits from SBT....no dice. Ski would start and run great on the trailer, would not perform on the water though....bogged down immediately with throttle. Switched back to original Mikuni carb kits....MUCH JOY!

Ignition coil replaced? Sounds strange that you would have enough spark to start then lose spark all of a sudden. The '96 uses a wasted spark system so BOTH plugs fire simultaneously...I would think you either have spark or you don't....but you indicate that this is exactly what you have.

The spark signal comes into the ignition coil (in the rear electric box) on the WHITE wire. I'd be checking (tracing wires) for continuity, good grounds, corrosion.....if you definitively rule out the carbs...then you have an electrical gremlin....always fun to chase them.

I will start chasing grounds and check for corrosion. Thank you.