Scag 25 hp Kohler quits but starts right back up

[Butch57]

I have a Scag turf tiger 25 hp kohler engine . When I start it up it runs fine for 10 minutes but it will quit suddenly , then starts
back up like nothing happened. May run for another 5 minutes ok then quits. I replaced the ignition coils, last summer thinking one was going bad. Hooking up a spark plug tester and an electrical probe it show ok till it quits suddenly, but starts right back up. I drive it between my house and my daughters to mow both lawns. It may quit 3 times between the two and maybe once after 10 minutes of mowing. But then again starts right back up. The electrical shut off at the carb is ok because it shuts off gas when I'm done mowing and the gas isn't still running the engine .Any thoughts would be helpful. Next thing I will again do is clean all the electrical limits and the wire connection going to the starter.

 

[Rivets]

First thing I would check is the kill wire coming off the coils. I would be looking for someplace where the wire is pinched or the insulation has been rubbed through, causing the engine to kill.

 

[BrentW]

It doesn't happen right after you refuel does it? I ran into this problem when I filled above the base of the filler neck. It gets to the charcoal canisters and kills the motor. It took a while for this problem to go away but it eventually did after I started filling to the recommended level.

 

[Butch57]

It will do it at 1/2 tank and up, never left it get below that point ( 1/2 way ) Will check the kill wire , that will take some time because the engine shroud is hard to move out of the way. The bottom of the shroud doesn't clear the frame which makes it hard to get at the wiring to check it out. Once the bolts are removed from the shroud it can be tilted only top forward. Not much of an opening to see and check the wire. Thanks for the thought.

 

[Butch57]

I never heard of a charcoal filter in the gas tank. Where can I find information on that and how much gas in the tank should I have when I filling it ?

 

[hlw49]

No charcoal canister in the tank it has a rollover valve and if the tank is over filled it will draw fuel right into the air filter housing and flood the engine. They put the valve in the tank and expect people to read the instruction manual and not over fill it. I have seen the tank filled so full it will shoot raw fuel out the exhaust pipe on the muffler. Manufactures need to redesign the system and get the rollover valve out of the tank. But then again people will still fill the tank too full and when it is cool is all right and when the mower sets in the sun and heats up the fuel will expand and it can do the same thing.

 

[MParr]

No charcoal canister in the tank it has a rollover valve and if the tank is over filled it will draw fuel right into the air filter housing and flood the engine. They put the valve in the tank and expect people to read the instruction manual and not over fill it. I have seen the tank filled so full it will shoot raw fuel out the exhaust pipe on the muffler. Manufactures need to redesign the system and get the rollover valve out of the tank. But then again people will still fill the tank too full and when it is cool is all right and when the mower sets in the sun and heats up the fuel will expand and it can do the same thing.

Ah, the benefits of EPA and CARB evaporative emissions rules!

 

[Butch57]

Ah, the benefits of EPA and CARB evaporative emissions rules!

The problem was a pinched wire under the shroud on the right side of the engine .

 

[Butch57]

Thanks to all who replied .