SV720s No Fuel/Hard Start

[rebelyell]

Two issues: Kohler SV720S is a pain to start. Won't turn over past the compression stroke. The compression release is messed up somehow. Valves are adjusted correctly, so I'm guessing now it's valve guides. Saw a video on how to tap those back in place and might give that a try this week. I'd rather try fixing this than buying a new head. This isn't as bad of an issue because I can at least get it started with a jump box.

The second issue is puzzling me. The carb isn't getting fuel. I can make it about 100 yards before it sputters for a few seconds and dies. There's very little fuel in the filter. This issue started when the motor was pointed down hill, now it won't run on flat ground. I've replaced the fuel lines, filter, fuel pump, and fuel cap. Still not getting fuel. I've cleaned the carb and checked the solenoid. All is clean with no obvious issues. Still no dice.

Is there something I'm missing?

 

[bertsmobile1]

Fuel supply will be debris blocking the fuel tank outlet, provided you have refitted the fuel lines correctly.
Cranking problem will most likely be a broken decompression unit on the cam.
Inlet & exhaust valves are the same length as are the valve guides so if one has moved it will be obvious by looking at it .

 

[rebelyell]

Thanks! Pretty involved process to get to that little guy on the cam. Do those fail often? I'm going to recheck valves and look for guide issues. Can the springs be removed with the head still on the engine?

 

[bertsmobile1]

Next to failed head gaskets it is my most common internal repair on B & S engines.

 

[Castleford]

I have a kohler sv740 courage that was the same as yours, wouldn't spin past the compression stroke,easily.
I had trouble setting the valves at first but now I find that I don't worry about the piston being at TDC as long
as the valve I'm NOT adjusting is fully open, then adjust the other one to .004/.005".
Then turn the engine over by hand until the valves have 'traded places' and adjust the second one to .004/.005".
Spin the engine over a few times (by hand) and re-check the lash to ensure the setting hasn't changed.

 

[slomo]

Most car engines can be set on the heel of the cam. Mower engine manuals say TDC on compression stroke. Remember there is another TDC on 4 stroke engines. You might have the cam in the wrong spot doing the valve adjustment.

Loose rockers will cause overly high compression. Some Briggs engines state put the piston 1/4" into the bore past TDC for clearance checks.

slomo

 

[Castleford]

Most car engines can be set on the heel of the cam. Mower engine manuals say TDC on compression stroke. Remember there is another TDC on 4 stroke engines. You might have the cam in the wrong spot doing the valve adjustment.

Loose rockers will cause overly high compression. Some Briggs engines state put the piston 1/4" into the bore past TDC for clearance checks.

slomo

I agree, but having set the valve lash the factory way 4 times with no change in the ACR function ( still hangs on the compression stroke) finally in desperation I just set it as described in post #5 and presto.....it spins over like a top ( and starts/runs )

 

[slomo]

I agree, but having set the valve lash the factory way 4 times with no change in the ACR function ( still hangs on the compression stroke) finally in desperation I just set it as described in post #5 and presto.....it spins over like a top ( and starts/runs )

Great that you found a solution. Good news. I normally follow the manufacturers procedures on stuff like this.

slomo

 

[rebelyell]

Updating the thread... Readjusted the valves because one of my adjustments came loose. Exhaust valve was 0.008" instead of 0.003"-0.005". Also replaced the starter with a new Kohler brand higher torque. Found rubber bits in the bottom of the tank that was causing the fuel issue.

Works as good as new. Thanks for all the help.

 

[StarTech]

Well you assumed something that was not present; the camshaft has no ACR.