Ski cuts out and dies while towing? Any ideas why?

[lineskier1925]

Last Monday after riding some surf in Rhode Island, I was towing my friends ski back to the launch and my ski (04 rockered superjet JM 735, B pipe, 38 carbs, Stock pump) started randomly dying. Pretty much would run for a quarter mile or so of towing and then it would just cut out and die.

After the other ski was towed back, my ski running on its own ran about the same as normal (wouldnt just randomly die). Any idea what would cause this case of the ski randomly dying? Too much load on the motor?

Just looking for some possible insights. I can try to provide further information if you need to know other details to try and solve this.

 

[lineskier1925]

The extra load would cause extra heat and also would demand extra fuel. Like having too Tall of an Impeller.

Was the Fuel Tank topped-off or was the Fuel Tank Level below half? When towing, the Ski Bow would be high and the Fuel would also slosh aft away from the Fuel Pick-Ups.

I'm guessing your Carbs were too lean for towing. May have been going thru some Piston Seizures. Check the Compression just in case.

Thanks for the insight on this! Im definitely going to check and see how the compression looks. I was hoping I was running a little more rich considering I've been going through plugs pretty often. Guess I'll have to keep an eye on how the ski keeps acting

 

[kevbo]

Carbs go lean when you are getting a lot of slack in the rope and there is a lot of jerking. The hard deceleration causes a momentary pressure drop in the carb because the fuel lines run forward. You may also notice pump vibration every time the ski jerks, the inlet pressure drops and a little cavitation occurs.