Super Jet Superjet backfires..?

[SmittySX]

I jut picked up a 96 sj with a riva head, pipe, and I haven't opened the electrical box yet, so unknown cdi. It ran terrible so I rebuilt the carbs with genuine Mikuni kits. When I was done it ran great. Revved and idled perfect out of water. I took it to the lake today and now it just backfires..? I almost poop my pants by how loud it was. What's the issue..?

 

[keith t]

Needles seats leaking fuel or timing out ? Maybe sheared woodruff key,

if you know carbs ok ( did you check pop offs when rebuilt ?) get the e box opened up and the front cover / flywheel off

 

[SmittySX]

I dont think its the carbs because it was running fine right after i rebuilt them..

 

[SmittySX]

Well Ive been hunting this problem slowly but surely..

1. I installed 3 different sets of carbs and i still have the same problem..
2. i took the flywheel cover off to find everything is the way its supposed to be. Woodruff key is perfect, No damage to the stator, flywheel looks good, and has a small timing advance.

Ive done some research and it looks like i could have a bad cdi.

Ive noticed that once i disconnect then reconnect my battery, i have to press the start button several times for anything to happen? ( could this be the CDI?) or just a bad button?

 

[Balduccimoto]

That could be faulty switch or starter solenoid. Have you changed the spark plugs to check for difference? I've had one NGK spark plug give me issues with backfires. I think it was defective.

 

[Big Kahuna]

Have you tried fresh fuel? Water in gas can make it run bad.

 

[SmittySX]

The ski won't even run.. I prime it and hold the start button. It gets plenty of gas. It's almost like its getting too much gas then BOOM.
even when I don't prime it, it's the same thing.

 

[Sparkplug]

Stop making it backfire. you can pop the crank seals out.

Im leaning towards the cdi, myself, if the timing at the stator is on and everything in there appears fine.

 

[SmittySX]

I don't keep trying to start it... It's backfired a few times only. I'm scare to even try and start the thing.

 

[SmittySX]

Someone on PWC mentioned that it could be my start switch?

when I disconnect then reconnect the battery, I have to press the start button several times for anything to even happen. It won't engage the starter for several pushes.

 

[hornedogg79]

Unplug your stop switch by the box (white/black) and stick a meter to the switch side to see if it is shorted. I had a similar issue last week and removed my entire electrical system before I found a shorted stop switch.

 

[SmittySX]

Just hooked up a different start/stop and its doing the same thing... I'm going to change the CDI out.

 

[SmittySX]

Well I just installed a 61x CDI ( 62t stator and flywheel). And it's doing the SAME THING!!!!! I'm stumped...

i tried
- 3 different sets of carbs
- flywheel ( woodruff key)
- checked timing on the stator
- start/ stop switch

It actually idled for a second with the different start switch, then died because I had The fuel off. Turned the fuel on tried starting it then BOOM....

 

[schicks]

have you looked at the reeds?

 

[SmittySX]

have you looked at the reeds?

yes I have. I replaced the stock ones with carbon reeds.

 

[SmittySX]

Now I'm wondering.. Could it be something stupid and simple..? Bad Plugs? Boots on the wrong cylinder? ( I know the boots are plug in correctly, I'm jut thinking out loud)

 

[sledneckddot]

My friend had the same issue last summer, it turned out to be a faulty stator

 

[tipafew]

I would try CDI if you have one.

 

[Big Kahuna]

He already did. did you remove the flywheel or just look down the trench? It could be sheared and moved over a few degrees if you did not pull it. Also, your stator could have gotten loose and shifted, same result.
you timing would be off and it is trying to light when your exhaust ports are open.

 

[SkiDiggity]

had the same problem ski would not run and it would back fire a lot.. changed the plugs and that was it.. try new plugs sometimes you just get a set of bad ones