Vaopr Lock??

Hi All, I have a 2013 Z915B Kohler CV740 725cc / Spec CV740-3144 Serial # 4310501211 Build Date 4-15-2013. Carb # 24-053-92 / 621030-141-2Z07... 700 hrs. OK with all of that... she starts up runs bout 15-20 mins and stalls….. I did all of the fuel delivery checks, fuel is being pumped to the carb inlet.... so after a cool down of an hour, I pulled the plunger on the shut-off solenoid started it and the same thing.... 15 min run time... stalls out.
I did check the fire at the plugs just after it stalled,, and had spark (although it wasn't as dark blue as I would have thought it should be)..... checked the fuel pump, and it pumped fuel....
Question 1) by removing the plunger, will that eliminate the solenoid getting too hot and failing? Id say yes. btw, the fuel shut off solenoid is the early type 1 wire connection.
2) What other heat sensitive electronics would cause the motor to stop
3) Is Vapor lock common? (There is no heat shield between the muffler or the carb.) I'd say an engineering mistake..

Other notes... No carb work as of yet but no water or dirt in the bowl. fuel lines are original but appear to be tight.

as soon as I figure out how to add a pic.... I will!!!

Fantastic..... 1st post and now we know I cant spell! :laughing:

What is common is suspended debris in the fuel tank being sucked down into the outlet and forming a plug.
When the engine stops, the debris floats off again.
The other biggie that is use ( or time ) related is a vapour lock caused by a blocked tank breather.

You check for the last by loosening the filler cap
you check for the first by removing the fuel cap then blowing back into the tank from the fuel line closest to the tank.
Pumps have a one way valve in them.

The solenoid does nothing but stopping the unburned fuel igniting in the muffler after you have turned the engine off.

Will it run with the choke on, when this problem occurs? We went around in circles trying to fix an erratic bog and power loss similar to what you described, with sons Z655 (Kawasaki). Ended up being a faulty carb. As bertsmobile1 above suggested, I would first check for a plugged tank vent, or other problem causing a vacuum in the tank.

Does the engine get weak, sickly sounding, then quit - or does it just shut off? First case might be the fuel supply, second case could be ignition. Spark plug firstly, then on to the coil/ignition.

tom3 said:

Does the engine get weak, sickly sounding, then quit - or does it just shut off? First case might be the fuel supply, second case could be ignition. Spark plug firstly, then on to the coil/ignition.

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Hey guys.... Went to a JD dealer that is more of "Turf Shop" the service manager gave me a little history about the Z915B... He said that model with the Kohler motor was a cheaper effort to get into the commercial zero turn market. Hence the China Motor, Nikki Carb (unserviceable carb) and DSAI ignition. Kohler sent out a service bulletin #259 dated 6-13 and revised 9-13. Discontinuing the DSAI ignition to a MDI system..... $100.00 fix...
The fuel system is clean and works well.... I ordered the conversion kit and will install it this weekend,,, I'll let you know how it turns out....
View attachment PB-259_DSAI_MDI_IGNITION.pdf