SJ dies when not under throttle

SXIPro

SXIPro

JM781 Big Bore
Location
Here on the 'X' mostly
2004 SJ JM781BB, stock 38s, BPipe, ADA Head, all your basics. Been running like a champ so far this year but a couple days ago it has developed a condition where if I'm messing around and come off throttle completely, like if I'm going into a power slide or something, the ski just shuts off...no stumble, no warning whatsoever, just shuts off. It will restart instantly with a press of the start button, though. I haven't touched anything yet, as carburetors are the devil's work.....you think maybe just turning in the throttle stop screw a tad may be all it needs? It just seems weird that this started basically out of nowhere.
 
iQRTurbo

iQRTurbo

Yes, crack your throttle plates a tad and it should stay running after a throttle chop. Hot humid muggy air moves slow and more throttle plate gap is needed than cool dry air.
 
SXIPro

SXIPro

JM781 Big Bore
Location
Here on the 'X' mostly
iQRTurbo said:
Yes, crack your throttle plates a tad and it should stay running after a throttle chop. Hot humid muggy air moves slow and more throttle plate gap is needed than cool dry air.
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Dude, I think you might have nailed it. The day it was doing this was the first 'tropical' feeling day I've ridden the ski with the new motor this season. Thanks!!!
 
SXIPro

SXIPro

JM781 Big Bore
Location
Here on the 'X' mostly
Big Kahuna said:
Pssst, check your idle!
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LOL! Well FOR ONCE it was something simple. I've never had to adjust my idle before due to air temp or humidity on any of my skis, but this is a new motor that was set up/tuned in May when there was about 0% humidity and air temps were in the 50s (water temp was in the 50s as well)) and the day it started showing this symptom it was at least 90 degrees, 95% humidity and water temps around 78 degrees. But hey, I learned something new, and that's always a good thing. And maybe others that experience this same issue will find this thread and be able to fix their ski in 2 minutes as well. Win/Win :)
 
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