surging Kholer engine

[smallenginerepairs]

I have a kt735 spec 0005g1 that is surging bad. I've set the valve clearance, new plugs, new oem (walbro) carb. I checked compression and one cylinder has 125 lbs and the other has 97 lbs of compression. does this indicate a blown head gasget? can there be any other issues?

 

[Bertrrr]

Does it surge under load when cutting Grass or just running at idle

 

[slomo]

Tank vent clogged.

Bugs, grass, dirt dobbers and grit in the fuel tank. Rubber pieces from tank cap deterioration in tank. All this trash will limit slash block flow from tank.

Fuel lines deteriorate from the inside. Replace all lines to carb.

Fuel filters plug up.

Using an old style gas can with the open top. Get a new style can to keep fuel fresher and less contaminated.

Gov-na' spring/linkage might be messed up, stretched or who knows?? Governor might be incorrectly set up.

Your second question about psi numbers. Indicates either valve issues or poor rings on one cylinder. Do a leak-down test.

 

[ILENGINE]

According to the service manual for your engine compression should be a minimum of 160 psi with no more than a 15% difference between cylinders. So you have bigger issues than just a surge.

 

[Douglas Lee]

Can you inspect the area around the suspected blown head gasket?
A cylinder leak down test might be helpful.
Keep us posted!
Doug Lee
*

 

[Auto Doc's]

I have a kt735 spec 0005g1 that is surging bad. I've set the valve clearance, new plugs, new oem (walbro) carb. I checked compression and one cylinder has 125 lbs and the other has 97 lbs of compression. does this indicate a blown head gasget? can there be any other issues?

Have you verified both cylinders are actually firing?

Spray a shot of water on each exhaust pipe and watch for it to boil off immediately. The one not boiling off is the none firing cylinder.

These V-twin engines will fool a person because there is no imbalance/ vibration. Pull the upper fan shroud and disconnect the single wire on each coil. Then fire it up and check for more power and no surge.
This usually means the "kill" harness to the coils is bad. The inline mini diodes typically fail.

Often times, people replace a coil and never check this harness.

If it has been jump started multiple times in the past, it will often blow these diodes out.

 

[slomo]

Often times, people replace a coil and never check this harness.

If it has been jump started multiple times in the past, it will often blow these diodes out.

Right right..........

 

[smallenginerepairs]

Right right..........

if the diode was blown the coil would not fire. I have put spark testers on both coils and both coils are firing. I also took the kill wires off both coils which would eliminate all wiring and still no fire on the one cylinder.

 

[smallenginerepairs]

if the diode was blown the coil would not fire. I have put spark testers on both coils and both coils are firing. I also took the kill wires off both coils which would eliminate all wiring and still no fire on the one cylinder.

also I have cleaned the fins on the heads now they were clogged enough to blow the head gasket on that cylinder, but I replaced the headmaster and that cylinder still will not fire.

 

[smallenginerepairs]

headmaster

headmaster not master.