Super Jet back again looking for advice on my sn... :/

[Krashtestdustin]

so i resolved my problem with the ski periodically acting like it was running on one cylinder, was a bad coil so i replaced it. well its about 3 weeks later and now another problem has came about. now my sn with a 61x/61x 701 in it now is acting up again. ok so the problem: i was out on the water last weekend and the ski was running fine then outta no where it just dies and wont start just constantly turns over, so when i hit shore i try and fire it up and it cranks so i take off again, i ride for about 5 minutes and it dies again, now this time i get to shore it it wont crank just turns over, so i check spark i have good blue spark on both cylinders, pull fuel line off carb, good fuel pressure, so i put alil fuel down the carb and it fires right up. so im thinking ok its the carb so i field strip it and clean it and take it for a spin and ride about 10 minutes and it does it again so im thinking wtf so i go on shore put some more fuel down the carb through the a/f and it fires up and idles for about 3 minutes and dies again. im at a total loss that can be causing this. its acting like its not getting enough fuel at random and thats whats killing it because theres periods of time that it will run completely fine for a hour or so and then start doing this? and advice or possible solutions? ive never had this kinda problem with my old 650sx so i dont know how to really diagnose it???

ok question number to took it out last weekend after doing a proper rebuild on the carb to see if it helped and its still doing the same thing but this time it lost all fire and till i cut the kill switch wire on my start and stop switch so the the stop button or lanyard doesnt work and fire returned idk what caused this random event either

might take it to the lake this weekend with a video camera just to try and get some footage of it acting up like it is so yall can prolly give some better advice, just have to find a camera

 

[garretonufer]

initial thoughts were a stuck needle but with a 61x/61x you're probably running a single 44. so that doesn't make sense. I had a similar issue of running good then dying. turned out to be a stuck needle in one of my 38's (dual set up) on a 62t/62t.

with mention of kill switch, now we are talking either a bad stop button or something in ebox. I'm at a loss on this one.

 

[Krashtestdustin]

yea i was thinking it might be a bad start stop switch but seeing as it was doing this prior to it loosing spark, it did it for almost a week prior to loosing the spark which instantly cleared up after cuting the stop switch wire so i know i have a bad stop button but i really dont think it was causing the main issue..a riding buddy of mine that used to ride back and the day and occasinally takes my 650 out said it could be bad reeds possible not sealing right and screwing up the vaccum in the cases or something like that ( i dont remember exactly what he said)

speaking of a 62t/61x motor, is it really worth the extra cash to switch to 62t cases and duel carb setup, im prolly gonna do a rebuild on it to eliminate the probability of it being leak in the cases somewhere and also because i did a comp test and im runnning 125psi on both cylinders which if memory serves me correct isnt it supposed to be around 150 stock?

 

[Byeai]

Yes but as u get higher in altitude u drop psi I thought I heard if u around the same in both your fine

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[Matt_E]

I doubt he has much altitude induced compression loss in Florida.

Clean the carburetor internal filters and inspect each carb's fuel pump closely.

And that compression is pretty low. Check it with a known good gauge.

 

[Byeai]

Lol thanks matt didnt look at profile

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[Krashtestdustin]

have cleaned the carb multiple times, just replaced the fuel pump the first time it started happening with the one from blowsion, and it is a known good gauge that i borrowed from my dads auto shop, could the low compression possibly be causeing my main issue?

 

[Matt_E]

Ok, so you cleaned the internal filter, made sure the pump diaphragm is good, inspected the pump check valves, made sure the jets don't have debris, the needle & seat is not worn, and the o-rings are still good?

The compression is low, but not so low for it not to run.

Make sure your fuel lines and fuel pickups do not have holes or splits in them. Also look at the tank check valve - the tank must be able to build pressure, otherwise it won't run well.

 

[Krashtestdustin]

as far as the carb the only thing that it possibly be is the needle and seat but even that looked like it was brand new all the jets are clear sprayed carb cleaner through them and went through it with the air nozzle on the compressor multiple times, diaphragm has no tears or anything noticeable, where are the pump check valves in the carb ive basically taken everything apart that i could on my carb and cleaned it all, your referring to the orings on the adjuster screws and throttle shaft correct? in that case they all seemed to be in good condition

all fuel lines are brand new, replaced them when i bought the ski, and the check valves good as well
should i rebuild the top end or do u think i could get by the rest of the season without it?

 

[Matt_E]

There are o-rings on the needle and seat. However, if those are worn, you get a rich condition and that's not what you got.
Fuel is not getting from the tank to the motor.
Disconnect the return line from the tank and crank the motor. There should be a pulsing stream of fuel coming from the return line.
If not, you have a pump problem in the carb or the pulse line is not giving pulse.

If you do have fuel coming out, it's not getting from the fuel line through the carb.

 

[Krashtestdustin]

theres fuel coming out the return
oh and the oring on the seat is good

 

[Matt_E]

Remove the flame arrestor and put your hand tightly over the top carb opening. Now crank and see if it starts. (This is like choking the engine and should result in a bunch of fuel being dumped in the carb throat)
It's possible that your needle & seat is stuck closed. There could be a bur on the pin that the needle arm rotates on.

 

[Krashtestdustin]

and idk if it matters or not but if i take my hand hand or rag and choke the carb with the airbox off fuel comes through the carb and it will crank up and run for about 10 minutes then die

 

[Matt_E]

Hmmmm....take a look at smooth operation of the needle lifting out of the seat.
Also, like mentioned earlier: Make sure the tank pressurizes. To check this, blow into the check valve of the tank and see if there's any air coming back out when you stop.

 

[js/sj]

Stator.

 

[Matt_E]

Yes, that explains why it fires up when he pours fuel down the carb.

 

[Krashtestdustin]

already tried replacing the stator with a new one, and no air comes out the check valve only lets air, which is what its supposed to do correct ?

 

[Matt_E]

Yes, that's correct.

Check needle & seat operation.

 

[Krashtestdustin]

what should i look for when checking the needle and seat? cause when opening and closing the needle with my finger nothing seems to stick?
what needle and seat should i buy to replace the current one on a stock set up with the stockk 44 single carb

 

[Matt_E]

what should i look for when checking the needle and seat? cause when opening and closing the needle with my finger nothing seems to stick?
what needle and seat should i buy to replace the current one on a stock set up with the stockk 44 single carb

It's possible that your needle & seat is stuck closed. There could be a bur on the pin that the needle arm rotates on.

take a look at smooth operation of the needle lifting out of the seat.

:bigok: