04 Exmark Lazer Z EFI loses power when hot!

rmsmx13

Forum Newbie
Joined
Apr 28, 2015
Threads
1
Messages
1
I have an 04 Exmark Lazer Z EFI (book says serial #440,000 and higher) , Kohler Engine CH740-0045, When mowing it runs fine for the first 30-45 mins. After that when you move left arm in reverse, then to go forward again it loses power an acts like it wants to die, if you move arms quickly to Neutral rpms pick back up and you have to ease forward to keep rpms up. Once you get moving it runs fine down strip until turning again. If I let the mower sit for 5 mins or so, it will run fine for 5-10 mins then start doing it again. It does seem to only be doing it with the left arm primarily, but sometimes does do it with the right. Also does it without pto engaged. Dealer couldn't replicate the problem when taken to them and one thing they said it could be is an O-ring in the pump. Oil Level is fine, hydro fluid and filter changed at end of last year level good as well. has approx. 500 hours. any help is greatly appreciated as I don't want to take back to dealer and have them tell me same again.
 

supertech

Member
Joined
Apr 28, 2015
Threads
5
Messages
44
I have a 2011 carbureted model right now doing the same thing, it has a 24 horse kaw engine. If you move left or right real fast or engage the PTO it will lose a cylinder. Im still running test don't know yet. Welcome to the world of EXMARK, lol.
 

supertech

Member
Joined
Apr 28, 2015
Threads
5
Messages
44
I have a 2011 carbureted model right now doing the same thing, it has a 24 horse kaw engine. If you move left or right real fast or engage the PTO it will lose a cylinder. Im still running test don't know yet. Welcome to the world of EXMARK, lol.

Found the problem, [ the governer has gone bad , lots free play in shaft, when senses a load it kicks in and opens the throttle more on carburetor, problem is the throttle blade stays shut and floods the engine almost killing it. its very erratic and will not do it all the time. Linkage rods and springs are fine , its inside the engine, that's the problem.
 

txwenger

Forum Newbie
Joined
Jul 27, 2015
Threads
0
Messages
1
I've an older Lazer Z EFI (Kohler) that would run good for awhile then start popping and snorting under load. In the end it was the fuel pump. When first started, the pressure was just fine but then would start to decrease and air would start entering the system.
 
Top