Super Jet Intermittent superjet Misfire?!

[SuperJetJordan]

Hi all,

First posts but have been browsing for a few months now.

I've got a '08 SJ and have been having some trouble with a misfire over the last two months.

It just started missing randomly one day while riding (saltwater).

Replaced plugs, ran OK for another half hour then misfire returned.
Cut back leads and replaced Plug terminals, ran fine for the rest of the day.
Next weekend took it out again and misfire returned after about 5 minutes of riding, new plugs, ran OK for another 5 minutes then returned.

Since then I have replaced ignition coil *afermarket* and leads with new plug terminals and boots - No change.
Swapped out CDI with known working one - Tested, ran OK for ten minutes and misfire returned.
Replaced entire stator assembly - Ran perfect for 15 minutes. Misifre returned.
Replaced spark plugs, drained fuel tank and fresh fuel and oil. - Ran perfect for about an hour, assumed all was good. Went to flush ski on trailer at home and misifre returned!!!

This is absolutely killing me! Any ideas on what else it could be???

The misfire occurs at all rev range but not very noticeable at idle.
Compression is about 130 psi both cylinders.
Also, starter will sometimes only click in e-box a few times, then it will start and run fine. (prior to ignition trouble)

Open to any help/suggestions!

Thanks,

Jordan

 

[loictahiti]

I suppose you need to change all your 16 mm cable ( black one engine to battery, red one , electrical box to battery, and starter to relay ), you seem's to be have a poor negative, and poor positiv too

 

[SuperJetJordan]

I took it for another run yesterday morning after running a new earth and it ran fine for about 40 minutes until I got a little bit of water under the hood and it missed at WOT. Also, the battery was almost dead in the morning? But nothing was left on??

Then a lot of water got in there and it ran like a bucket of crap and I had to limp it home...

So something is getting wet that shouldn't or water in the fuel??

I'm putting in new Deutsch connectors for stator and start stop switch tonight and have re-wired the bilge to be switched on the neutral side. I'm running out of ideas!

 

[SkiDiggity]

130 in each cylinder seems low to me isn't it supposed to be 150? Check your ground wire too it may be loose

 

[SuperJetJordan]

Turns out it was the spark plug boots. I was impatient and used some old auto ones, new MSD HEI ones arrived in mail on Friday and ran fine most of the weekend, til I subbed it too far and they must have got water in them still.

Thanks for the help everyone.