300/440/550 85' JS440 stalling problems

[PoRunner]

First of all I want to say hello to you all. There is some excellent information I have stumbled across on this forum so far!

So I have had an 85' JS440 for about a year now and have had a strange problem occuring with it. It starts up instantly in my garage and even when I put it in the water at the lake, but after riding it for about 15 minutes it shuts off and will not start again for a couple of hours. I checked the black box near the back of the engine compartment and it is completely dry. I resealed it just in case and haven't been able to test it yet. I am headed to the lake in a week and want some ideas for what to check if this happens again. I have zero knowledge when it comes to this motor unfortunately so any input would help tremendously.

Sorry if this topic has been beat to death but I have no clue where to go from here.

 

[Quinc]

Next time it happens pull your spark plug out and check that it has spark
check/replace the check valve on your air tank.
Rebuild your carb
Check fuel lines for cracks, easy and cheap to replace them.
put a new gasket on your intake manifold

Download the manual here:
http://www.pwctoday.com/showthread.php?t=40122

 

[PoRunner]

So if it happens and I pull a plug and no spark, where is my go to? I have a known good carb on it currently and the black electrical box towards the rear is properly sealed.

 

[Quinc]

So if it happens and I pull a plug and no spark, where is my go to? I have a known good carb on it currently and the black electrical box towards the rear is properly sealed.

Than you know you need to check your elect system. First thing to check is all of your grounds and go from there.

 

[PoRunner]

Excellent. Thanks for the advise. I'm going to start with replacing all of the grounds tonight and double check all of the fuel lines.