RESTO Seadoo xp stalls after 30 minutes of riding

[Seadoosxp7201]

Seadoo xp 720 will start up and run great... once I get the jet ski thrown around and start opening it up it seems to stall like the cord was off and not start back up... sometimes it will start up and sometimes it just flat out will not start.. I have replaced the carbs with kits I have replaced all fuel lines select valve and inline filters I have replaced all the filters the ski is at 145 -150 psi compression.. the tank has been cleaned out the head has been off and the piston and cylinder look good I have a new head gasket in it because it had a water leak from the o ring head.. I have no idea if it's got crank seal inner thats out or a bad rotary valve? I'm so confused I will try and post a vid.. and I do have spark and fuel going to the carbs or it could be getting stuck at the crank seal? Or rotary valve? Hope this sort of explains my problem I have had it on the hose and it runs fine it's when you put a load on it for around an hour she just dies and will not start back up once I get it home from the lake? Guess what the darn thing starts? That's what I have it narrowed down to I have a new coil in it have cleaned mpem cords red and black ground and have blown out.. any help would be great I have tried running it without cap off same thing... and compression is still 150 ish thanks branden,

 

[darren shumbo]

Check your fuel tank vent....sounds like after an hour the tank is getting a vacuum and starving the carbs and stalling the engine...as soon as it stalls, check for spark...if you have a good blue spark, then it is fuel related......also as soon as it stalls, open the fuel tank and listen for a hiss of air going in....if it hisses, you have a plugged fuel tank vent tube...

 

[Seadoosxp7201]

Seadoo xp 720 fix

Thanks Darren, I have tried that and yes I do have spark it doesn't look blue lol.. but I'm thinking my jetting is off it's got ocean pro arrestors I'm thinking of setting the stock air box on and running the stock jetting ... seems odd to me I'm thinking the fuel and air mixture is screwed up I could probably go up 5 sizes on the jets that air box adds a ton of open air which probably screwed my carb jetting it's running lean for sure...

 

[gr8shot10]

i dont know a ton about these things but from doing tons of reading on threads ive read some will do this when running to lean they will stall out due to the piston seizing in the bore from running to lean and getting too hot, not sure if its your case but i think getting the mixture right might be a good place to start

 

[hotrodssnova]

That's called a quick stick. Does your temp sensor work? How about the beeper?
Are you getting a good stream from the rear pisser?
Saltwater in its past?

 

[manolocross]

Check your fuel tank vent....sounds like after an hour the tank is getting a vacuum and starving the carbs and stalling the engine...as soon as it stalls, check for spark...if you have a good blue spark, then it is fuel related......also as soon as it stalls, open the fuel tank and listen for a hiss of air going in....if it hisses, you have a plugged fuel tank vent tube...

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