1992 sp will run 15 seconds exactly and then dies

[dmacheel]

The sp cranks rite up and will run 15 seconds and then dies, it doesnt matter if you have it at full throttle or if its in idle. New plugs, new gas, 185 psi in each cylinder. Carb was just cleaned. Please help!!!!!!!!!!

 

[manolocross]

185 psi????thats way too high....engine must be full of oil...

 

[dmacheel]

The motor is bored 1mm over and it has the west coast racing head thats why the compression is high

 

[Dr Honda]

Yep... 150 psi is a fresh engine. 185, it will be melting things, unless it's just oil.

It could be a bunch of things. Have you narrowed it down at all? Electrical, fuel, ect.

 

[dmacheel]

Tried pouring fuel directly in the carb during the time it shuts down and it still dies. Not sure about the coil. I know when it shuts down you can immediatley crank it back up then you have 15 seconds and dies. Revs fine during that time it also has the west coast rev limiter set at 7500 rpm.

 

[Dr Honda]

Tried pouring fuel directly in the carb during the time it shuts down and it still dies. Not sure about the coil. I know when it shuts down you can immediatley crank it back up then you have 15 seconds and dies. Revs fine during that time it also has the west coast rev limiter set at 7500 rpm.

Then it sounds electrical to me.

I would start by removing the aftermarket rev limiter.

 

[Minnetonka4me]

Im pretty sure the old ones dont have any kind of timer in them like the DESS machines do....weird problem!

 

[dmacheel]

In my manual it actually says the ECM and relays come a default 20 second timer, what ever that is?

 

[Minnetonka4me]

Well I would guess your MPEM is bad if it says that in the manual. The 92 MPEM sucked...you wanna get a 93-94 out of another 580 machine.

 

[dmacheel]

Is there a way to test the mpem? Would you go aftermarket? I know this ski is old but it is fully tricked out, exhaust, waterbox, prop, ride plate, high compression pistons, head.....etc...... Do I need the aftermarket rev limiter installed? also parts arent easy to find? And will any mpem that runs the 587 work??? Sorry for the questions!!!!!!!!!!!!!!

 

[deepdiver]

I think there are tests for the MPEM in the manual. Also search on this forum for "MPEM" or "ECM" for older similar posts and answers, including repairs and sales.

 

[Minnetonka4me]

Only the MPEM from a 93-94 587 will work. I perfer OEM. Yes, if its modded you will want a limiter in there. I have a brand new one if you need one.

You can take that rev limiter out of the mix for testing purposes.

 

[dmacheel]

I didnt know you could remove the rev limiter??? In case your wondering I didnt do all the work to the ski, my buddy had it all done? I guess that is definatley something I need to try!

 

[dmacheel]

Also before this problem started happening, last year, the ski didnt want to cut off when you hit the stop button you's have to hold it down for 5 to 10 seconds, same thing for the lanyard post, when you would pull the key it would someetimes take 5 to 15 seconds to shut down, Does this also sound like MPEM problems?