2005 ExMark Dies out when Warm 27HP Kohler

[onehandman]

Hi everyone,

I was given a 2005 Exmark Z laser 60 inch cut with a kohler 27HP. It is not EFI. Lately when the mower gets warm it will start to bog,backfire(out exhaust), and die out when mowing/under load. If you choke it it seems you can keep it from dying out, but it still doesn't run correct. The machine does have 2100 hours, but it has something going on(not base engine), both cylinders have over 100PSI and I have check valve lash. All of the safeties were previously removed so I do not expect it to be a safety switch as the cause. I believe something is getting warm the from engine and starting to fail, and was hoping this may be something common on this year mower.

Thanks in Advance.

Paul

 

[ILENGINE]

Depending on Kohler engine 100 psi could be considered way too low. What model of 27 hp Kohler is on that mower.

 

[onehandman]

Hi ILengine, I believe it is a CH740 or CH750. I had throttle wide open, and let the engine crank over 3 revs(typically how I would do a car). I'm stumped on why it runs really good the first 15-20 min, then goes to sh** after that.

 

[ILENGINE]

The Command series should have a minimum compression of 160 psi. the other things that come to mind is ignition modules cutting out when hot, may need to check for spark. Also the fuel solenoid on the carb could be doing the same thing. When It quits I would turn the key off and back on a couple times to make sure you can hear it click on the carb. the last thing could be fuel pump released which could be faulty fuel pump but depending on type of pump the lower than normal compression can effect fuel pump pulses if vacuum activated.