Super Jet somethings wrong with my ski. cant figure it out

[rossthaboss11]

i was riding all day and then i felt something go wrong with the way my ski was running. Immedietly i thought i blew an O ring out on my head cause thats happened before and its what the symptoms of the ski felt like. So i went in right away. I checked compression and they were both 180psi. so next i checked to see if both plugs were getting spark cause it kind of feels like only one cylinder might be firing. but they both sparked fine. The motor sounds loud at times, especially at about 25% throttle. It rev'd up much higher on the trailer then it did before for some reason. when i give it gas while riding it doesnt really punch hard and is just missing its beat. any ideas?

 

[D-Roc]

exhaust leak?

 

[vomitspot]

busted reed

 

[rossthaboss11]

the exhaust coupler was starting to come a little loose so i tightened that but no luck there. ill have to check the reeds

 

[QuickMick]

Broken defuser

 

[NVJAY775]

Loose stator maybe. Happened to me a couple times.

 

[rossthaboss11]

whats the defuser?

 

[D-Roc]

check all clamps and couplers on exhaust and even the chamber if it was rubbing on something it could have finnaly worn thru. broken reeds will loose you performance and make difficult starting when the motor is hot.

 

[rossthaboss11]

reeds are fine from what i can tell by looking down the intake manifold with a mirror and feeling with my fingers. the exhaust coupling had about a 2 inch long rip in it so i immediately thought that was it. but the crack doesnt go all the way through and there was plenty of silicone right on the other side so no way it was leaking there. pissed that i took the exhaust off cause its a type 4 and a PITA to put back on. now what to check? maybe the stator but i doubt its that. i used red loctite on those screws

 

[smoofers]

reeds are fine from what i can tell by looking down the intake manifold with a mirror and feeling with my fingers. the exhaust coupling had about a 2 inch long rip in it so i immediately thought that was it. but the crack doesnt go all the way through and there was plenty of silicone right on the other side so no way it was leaking there. pissed that i took the exhaust off cause its a type 4 and a PITA to put back on. now what to check? maybe the stator but i doubt its that. i used red loctite on those screws

Did you try riding with the hood off? That's an easy way to determine if an exhaust leak is the problem.

 

[rossthaboss11]

i cracked open the hood while laying down and there was no smoke coming from inside. On the hose it didnt seem like there was any exhaust leaks and no oil coming our anywhere. maybe something is wrong mechanically with the motor?

 

[Liquid Graffix]

I'm with Vomit on this one. Pull the manifold off and pull the reed blocks. A mirror is ok, but you won't know for sure unless you pull them to inspect them. There could be a crack that you missed. At the very most, your out a couple bucks for new gaskets but it's worth it imo.

 

[rossthaboss11]

took the manifold off and the reeds are perfect.... so unless if its sparking at the wrong time for some reason then its gotta be something mechanically wrong in the motor or the exhaust had an issue. i cant think of anything else. possibly a fuel line is clogged so one cylinder has no or little fuel?

 

[smoofers]

If you have a spare start/stop switch, you might try that. This is starting to sound exactly like a lanyard post that is going bad. Has happened to me on about 3 switches now.

 

[rossthaboss11]

what does that cause? the spark to be intermittent? couldnt cause just one cylinder to not spark so wouldnt the ski just shut off if it was stopping the spark here and there

 

[KR]

If you have a spare start/stop switch, you might try that. This is starting to sound exactly like a lanyard post that is going bad. Has happened to me on about 3 switches now.

What?

 

[smoofers]

what does that cause? the spark to be intermittent? couldnt cause just one cylinder to not spark so wouldnt the ski just shut off if it was stopping the spark here and there

When my switches have gone bad th ski will run on one cylinder out of nowhere, or it will act like it's bouncing off the rev limiter at low rpm. Check your start/stop switch

 

[steve-uk]

number of things can cause a bad spark, we chased a similar issue and pretty much replaced everything

bad/weak spark could be:

bad ignition
pinched wire in ebox (happens alot)
bad ground
bad HT leads
Bad Start/stop
Bad Stator
sheared key in flywheel
Wrong plugs
bad plug caps
not enough cranking juice in the battery
etc etc etc

have you turned the ski over with plugs on head? what did you see? you mention intermittent sparking but dont say your experienceing it?

we had this problem on a ski and it would alternate between plugs...

 

[rossthaboss11]

yes i held the plugs against the head and turned it over and both sparked perfectly. nice and bright and continuous. the motor itself cranks normal, no noises or anything. the battery is new and fully charged. i guess my next step is to take the e box apart and check things out in there and see if my stator is still tight

 

[steve-uk]

if you got perfect spark id be looking elsewhere..... unless your convinced its electrical

you mention fuel starvation at one point, do the simple stuff... have you checked the one way valve on the tank and your filters?

not sure what carbs your running but have you cleaned them? the little filters inside clog up easy.

its still sounds a little from your original post like an either a fuel starvation issue or an exhaust leak.. what exhaust you running? if its a b-pipe the blue couplers sometimes get a tear, check on the hull for any witness marks where the exhaust has blown against the hull