Superjet Misfire

A

AusAndrew

Location
Australia
Ok first off 96 SJ with a bog standard engine.

Last weekend I was riding in the surf when the ski started to misfire really bad. I noticed when starting it I would get electric shocked through the throttle lever. I thought it looked like a damaged ignition lead as one of mine was broken (had been for ages) and seemed to have finally given up.

So I replaced the leads with Champion ones and it seemed to run ok right after replacing (on the trailer). However later on in the week it started running really badly, missing when it was revved. I fiddled wih all sorts of things fuel related and changed the plugs (B7HS) and seemed to get it running ok (I had also had the tank out and thought I may have pinched a fuel line).

Took it out today and all was not well. It seemed to miss worse once I had let it idle and then revved it. It would cough and splutter and sometimes die. By 'pumping' the throttle it came back and I could continue to ride. But basically it got worse to the point where it was unrideable and I gave up. I did notice that standing next to the ski (in the water) with my hand on the tray I got shocked when I pushed the start button.

Came home and checked everything. Took the carbies apart and cleaned them, checked the reeds were ok. No luck.

Could it be the new leads, or using B7HS not BR7HS (I have always used the non resistor plugs). Or was the initial problem not the leads?

Any suggestions? Or any troubleshooting ideas?

Cheers
Andrew
 
A

AusAndrew

Location
Australia
Just to add to the info measuring between the plug leads I get 16.5k ohms. The book says I should see 4.5k ohms; I assume the leads I have put in have more resistance than the std superjet ones. Will this cause any dramas?

Cheers
Andrew
 
keith t

keith t

Location
Braapp factory
I had a bad misfire on my superjet that only appeared in saltwater - i could actually get a belt of the engine - it turned out to be the exposed live terminal on the battery shorting out once saltwater got in the engine compartment. I covered the terminal in grease and the misfire went away.

Now you have posted about the ignition lead resistance i think you need to concentrate on that first.

I would cut back the plug leads and check measurements, then assuming theyre good - make sure you crimp the plug terminals on good - saltwater will find its way into the coil and leads if they arent sealed good and proper
 
surfjunkie

surfjunkie

Location
deland fl
keith t said:
I would cut back the plug leads and check measurements, then assuming theyre good - make sure you crimp the plug terminals on good - saltwater will find its way into the coil and leads if they arent sealed good and proper
Click to expand...


x2

the time i had problems with misfiring and getting that tingle in the finger, it was bad plug wires. corroded about and inch back from the plug. trimmed back past the spot and was good to go.

good luck
 
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