ski breaks up after it gets warm

[dabeetereater]

got a pretty healty ski, 62+/61X setup with stock 61x electronics
ski runs great when its cold and for about 20-30 min, its not overheating, but after you ride it for a while it breaks up under WOT, it did it before when it blew a oring in the head and i fixed that and a leaking exhaust mani gasket,

now it only does it when its been riding for 20-30 min,
i can come in let it cool down with the hood open for 30 min and im good to go for another 30 lol

feels like ignition related its not totally droping a cylinder it just feels like a boosted car with not eneough spark or it blowing out a little

just looking for some ideas

 

[SJBrit]

Sounds like it could be a bad coil.

 

[chriselmore_1]

Small exhaust leak?

 

[WFO Speedracer]

Could also be bad spark plug boots, I have replaced many bad Yamaha spark plug boots over the years.

 

[SJBrit]

Could also be bad spark plug boots, I have replaced many bad Yamaha spark plug boots over the years.

Yes, good point. When you look at the plug boots, take a look at the plug wires too. Grab a few strands with some pliers and pull - I bet some will come right out. Sometimes you have to chop a couple of inches off before you get back to good wire.

 

[dabeetereater]

yeah i was thinking coil to i just wanted some input,

and i already choped 2 inches off the wires it helped but did not solve the problem
the boots look pretty good also

and im pretty dam sure i got the exhasut leaks taken care of,
i think im down to the coil,
and i need to get or modify my cdi i need more rpms baddd

 

[BruceSki]

stator. especially if it takes a while for it to happen. I'ts once it gets hot. Sometimes I have had to trim back 3 inches of plug wire to get good solid wire too.

 

[WFO Speedracer]

Yes the wire Yamaha uses is crap, you can get good ignition wire at Napa sold by the foot then make a tool and cut the remaining wire out of the coil, push the new wire into the post, dribble some epoxy past the wires and it will usually work much better.

 

[dabeetereater]

hmm that does nto sound like a bad idea, i got some really good wires off one of my vw's i could probably try that, im gonna try another ebox my buddy has and seee what happens im thinking its the coil but wont know til i try so

 

[WFO Speedracer]

Its always a good idea to track the problem down with known good parts if you have access to them.

 

[dabeetereater]

yeah my friend has tons of yami parts laying around gonna start swaping stuff this weekend lol and see what happens

 

[Captain PegLeg]

same problem with a ski i am building.... I sent my coil and my stator to jet ski solutions for reman.... I will let you know how it works after this weekend!

 

[waxhead]

Replace the exciter coil
Its getting hot and shorting out , this reduces the amount of current to run the igniton and so it misfires etc
When it cools down the short goes away and the ski runs again until the coil heats up comprimising the insulator in it

This is a extremely common yamaha fault , Yours is not so bad it normally takes about 10 minutes for this issue to show up
You get twice as long

 

[SJBrit]

Replace the exciter coil
Its getting hot and shorting out , this reduces the amount of current to run the igniton and so it misfires etc
When it cools down the short goes away and the ski runs again until the coil heats up comprimising the insulator in it

This is a extremely common yamaha fault , Yours is not so bad it normally takes about 10 minutes for this issue to show up
You get twice as long

Yup. It's actually an extremely common coil fault in general - I've had the same happen on a car, mower, ski....