91 650 superjet stall after 45 mins of riding

[catzass_fireman]

Hi Gang got a little problem. I just got this ski have had it on the water twice. Both times out ski just died all of a sudden and wouldn't restart. First time it happen I thought maybe I'd ran it out of gas so I switched to res , choked it and it started. But it only ran long enought for me to turn it around get it up on plain and then it died again. would not restart so I got a tow to shore from a nearby boat. (maybe 20 mins towed) When I got to shore checkk and it wasn't out of fuel and it started right up. After first day I drained old fuel, put in new plugs ( old plugs did look all right , brown in color) Second day seem to notice "stumbles" at wide open throttle. It died all of a sudden three times first two times the ski started right up, third time it would not start but the first crank sounded like it fired, then ski sounded like it had no fire. I again was towed this time while being tower I tryed to start the ski after maybe 10 mins , it restarted and got me back to shore, but did seem to stumble while at full throttle. After second day I checked the plugs the were kinda greyish. I also checked high side of carb 1 and 1/4 turns out. Ski seems to start and run strong. I'm at a loss for what to check. I'm thinking some sort of heat problem but I'm at a loss as to what the problem is. Thanks for reading my sad story and I welcome any ideas for what to check.

[David3aces]

Re: 91 650 superjet stall after 45 mins of riding

I think it's the handlebar switch and or carb....the way it instantly stalls makes me think it's the handle switch and the speed problem is the carb (water?)

[K6jet]

Re: 91 650 superjet stall after 45 mins of riding

I think its probably electrical, check the killswitch like david suggested, there IS a white/black wire from the Killswitch connected under the hood right? If so, disconnect it, and try running it like that for a while, to shut it off, pull the choke and wait for it to flood.

[DankBud]

Re: 91 650 superjet stall after 45 mins of riding

Check to see if Check valve on Fuel tank is working properly. If it is restricted you will get a little riding before it creates a vacum in the tank. (normaly about 20-30 min)

[catzass_fireman]

Re: 91 650 superjet stall after 45 mins of riding

Dankbud, that is one of my next checks. I took the ski out today. Had a Mechanix friend with me, we tweeked the carb settings because the plug showed a slight lean burn. This only created new problems flooding the ski. The fuel filter was dirty so I changed it. After fuel filter change and carb tuned close to where it was when we started I went out and ran for aprox 45 min to an hour. It ran great for quite a while. then it started to seem bogged down at wide open throttle. I could standup and ride wide open no problem where as a few min before I couldn't. Then it died like before. Tried to restart it with no luck. I did open fuel cab but didnot hear an intake of air. Tried disconnnecting lanyard several times to no avail . what seemed to work in the end was switching to res choking the ski and she started right up(blowing my water shoe off in the process, sure glad it floats they were brand new.) I shut the ski off put my shoe back on and switched the fuel back to "on" ski started right up and seemed to be back to normal. I could no longer stand and ride wide open without being on the edge of out of control. I went on in to shore and check the plug it was slightly wet but had good color. One thing I noticed fuel level appear to be about as it was the pervious two times the ski has died like this. This makes me think something is causing a vapor lock type condition when I reach that fuel level. I figure I'll ckeck all the fuel tank vent hoses tommorrow.

[catzass_fireman]

Re: 91 650 superjet stall after 45 mins of riding

Is the check valve on the fuel tank suppose to flow both ways? I removed it and it offers no resistance either way. I was under the impression that it was only suppose to flow one way.

[K6jet]

Re: 91 650 superjet stall after 45 mins of riding

Well, it is supposed to only allow air to flow one way, to the inside of the tank, it lets air in, but not out. This may be your problem, but most likely not if it was letting air in. Since jetskis are overturned so often, the coast guard requires that their fuel systems be sealed. A pressurized tank really helps with cold starting (as air does build up to around 3 or less psi over time) but after its starting, if its letting air in, it should be fine. You'd still want to replace it though, but it doesnt sound like you have a vapor-lock problem.

[yamahawaverunner56]

Re: 91 650 superjet stall after 45 mins of riding

what could be happening as you siad you could nto get it restarted but that once and ever time there after it restarted when it was a cold engine again you could have the cdi shorting to ground killing spark once it is hot enough then after it cools off the wire contracts again allowing ti to spark and start

[K6jet]

Re: 91 650 superjet stall after 45 mins of riding

well, if the above is correct, try to take it out again, and when it (or if) it fails to start again, you can pull your plugs, and (MAKE SURE YOU DO THIS OR YOU WILL BREAK THE CDI) ground the plugs to an unpainted bolt on the head. Check for spark. If there is spark, well then its carburetion, clean them and rebuild them to start with. If there's no spark, try unplugging your killswitch, and see if it starts, if it does, you wont be able to shut it off with the killswitch, so be ware, you will have to pull the choke and wait for it to bog down (like 5 seconds)

[yamahawaverunner56]

Re: 91 650 superjet stall after 45 mins of riding

no from what you siad about the fule level saying baout the same i dont think it is electrical it could be vapor locking i would check the temp of your fule (approx.) if it is above 176 i think it will begin to cause air bubbles causing a vapor lock if enough air bubbles

[catzass_fireman]

Re: 91 650 superjet stall after 45 mins of riding

Thanks for all the good ideas. I swiped a good check valve off a junk ski I have and have marked my "problem fuel level. I'm going to take it out again in the next day or two and see what it does. If it doesn't solve the problem I will try a few of your other suggestions. In case you're wondering how I seem to know the fuel levels. When I cleaned all fuel out the after first day I marked the tank after puting in 5 gals so the last time I took the ski out I filled the tank back to that level. Just hav a new crack head idea. :emoticonn I havn't looked at the fuel pickup closly yet, is it possible I have a (hole in my straw) type problem? When you have a hole in the straw of your big gulp its not a problem until you get below that level of soda, then you still get some soda even though you do suck air too. (**** I wish my garage had a light, I'd go look at it right now.:emoticonc

[K6jet]

Re: 91 650 superjet stall after 45 mins of riding

that is highly possible and you should take a look at it ASAP and see if its cracked up