26 HP Kohler Courage on Craftsman DGS 6500, intermittent surging

[GPB]

I recently bought this tractor used and since getting it home it has surged or lost power (with a gas smell when it loses power) and then surged back to full power. It happens both when mower is engaged and not. What I've looked at so far:
-tested the solenoid under the carb and it worked well.
-removed the existing fuel and put fresh ethanol free unleaded in.
-sea foam soak in the carb (while still installed, I did not yet tear it down)
Plugs look equal and dry. I have heard the fuel cap can form a vaccum, but mine seems fine.

Today I took the solenoid off and removed the plunger, magnet and spring and reinstalled the solenoid body along with an in line fuel shutoff valve. I was thinking it was possibly working intermittently. I drove it while mowing for 45 minutes after that with no issues. Hooked up my leaf vacuum and pulled that around for another hour with no problems. This whole time the hood was still sitting in my garage, so while unloading one of the last loads of leaves, I put the hood back on. Surging returned. Took it off and it went away, almost like a switch.

Any ideas on this one? I'd like the hood on when the snow starts flying as it came with a snow blade.

 

[mechanic mark]

Searching Model For Search Your Way 91728745 | 2 | SearsPartsDirect Check air filter for replacement.

Free Kohler Service Manual Downloads : Kohler Engines and Kohler Engine Parts Store, Genuine Kohler Engine Parts scroll down to locate SV735

Read fuel system in your manual, specifically carburetor, remove, clean, inspect per manual instructions, you may need to purchase overhaul kit.
Regarding coil or ignition module you have 2, testing procedure page 37. Purchase an inexpensive multi-meter to test, it will serve you well in years to come.

 

[GPB]

Thanks for the reply mechanic Mark. I forgot to add that to the list of things done. That was actually the first replacement I did on this new mower (new to me anyway). In other threads I have seen some recommend new coil/ignition modules. Given this issue comes and goes, I don't know that I can really give that a good test. Any credence to looking at the coils or ideas how to assess it?

Thanks again Mark, I will try the carb this weekend and have ordered the multimeter.

 

[Fish]

You need another digit in your craftsman number, just wanted to see if there was any safety switches on your attachments.

 

[Fish]

Your ignition system looks to be getting into new, expensive territory........

http://www.smallenginesuppliers.com/html/engine-specs/kohler/PB-259_DSAI_MDI_IGNITION.pdf

 

[Fish]

But my "kneejerk" opinion on your problem, makes me think that you have some moisture/dirty water slinking around in your fuel system. I would run some fuel dry and
mow until something serious may happen, otherwise, just burn that moisture through the system.

 

[cambre]

I recently bought this tractor used and since getting it home it has surged or lost power (with a gas smell when it loses power) and then surged back to full power. It happens both when mower is engaged and not. What I've looked at so far:
-tested the solenoid under the carb and it worked well.
-removed the existing fuel and put fresh ethanol free unleaded in.
-sea foam soak in the carb (while still installed, I did not yet tear it down)
Plugs look equal and dry. I have heard the fuel cap can form a vaccum, but mine seems fine.

Today I took the solenoid off and removed the plunger, magnet and spring and reinstalled the solenoid body along with an in line fuel shutoff valve. I was thinking it was possibly working intermittently. I drove it while mowing for 45 minutes after that with no issues. Hooked up my leaf vacuum and pulled that around for another hour with no problems. This whole time the hood was still sitting in my garage, so while unloading one of the last loads of leaves, I put the hood back on. Surging returned. Took it off and it went away, almost like a switch.

Any ideas on this one? I'd like the hood on when the snow starts flying as it came with a snow blade.

I have same engine as you do on my Craftsman. I don,t have an answer for your hood problem but was the hood causing your problem? I cannot get my governor adjusted the way it should be but it runs good other wise. Cambre

 

[mechanic mark]

I have same engine as you do on my Craftsman. I don,t have an answer for your hood problem but was the hood causing your problem? I cannot get my governor adjusted the way it should be but it runs good other wise. Cambre

cambre, page 28 in Kohler manual above #2 shows governor adjustment for SV735 engine.

 

[cambre]

cambre, page 28 in Kohler manual above #2 shows governor adjustment for SV735 engine.

Thanks m. mark

 

[GPB]

You need another digit in your craftsman number, just wanted to see if there was any safety switches on your attachments.

That should be 917.287451, thanks.