Kubota ZG20 Kohler ch20 horizontal

Timbo1959

Forum Newbie
I have a Kubota with a kohler CH20 twin cyl. horizontal with 1300 hrs. It's been a great mower. Started bogging down under a load and had a pretty bad oil leak. Had to remove the motor to change coils and crankshaft main seal. Cleaned up and found another oil leak at oil cooler. Back together started right up. 15 to 20 minutes into cutting started bogging down again.
I noticed an oil leak on left valve cover. Did a compression check. Both cylinders read a perfect 155 psi. I'm thinking it may be the breather. Any suggestions would be appreciated.
 
I have a Kubota with a kohler CH20 twin cyl. horizontal with 1300 hrs. It's been a great mower. Started bogging down under a load and had a pretty bad oil leak. Had to remove the motor to change coils and crankshaft main seal. Cleaned up and found another oil leak at oil cooler. Back together started right up. 15 to 20 minutes into cutting started bogging down again.
I noticed an oil leak on left valve cover. Did a compression check. Both cylinders read a perfect 155 psi. I'm thinking it may be the breather. Any suggestions would be appreciated.
If your compression tester is accurate, then 155 psi is really excellent. I would suggest a leak down test. Also, possibly removing the carburetor and cleaning it. 1300 hours is fairly high hours, so I find the compression tester results suspect.
 
If your compression tester is accurate, then 155 psi is really excellent. I would suggest a leak down test. Also, possibly removing the carburetor and cleaning it. 1300 hours is fairly high hours, so I find the compression tester results suspect.
Actually 155 is below the Kohler specified 160 psi for the Command series engines.
 
Spray each exhaust outlet pipe with a spray bottle of water and see if they both burn of quickly. This sound like one cylinder is losing ignition fire.

I'm not sure if this engine has diodes in the ignition kill wire harness, but if it does, they would be suspect. You can pull the cover and unplug both coils' kill wire and see if the problem goes away. To shut the engine down, choke it or shut off the fuel.
 
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