Starting Problems

[bob]

John Deere STX 38 with Kohler engine, Command I think and 12HP. Had problem with gas leaking out carb. Ended up replacing carb with Ebay purchase. Now I am having problem with starting. Carb is gravity fed. When starting it will try to start once and thats it. Will not keep running or even try to. If I choke it is same thing. Turn key off and try again it will probably do the same. If I shoot a little carb cleaner in carb it will try to start once and that it. After attempts at starting gas will start running down muffler pipe. Not sure what that is about. Need some direction of what to look for. Thanks

Blair

[acscolo]

Sounds like you have a leaky needle and seat.
I would take and rebuild the original carburetor that came with the engine as you are having trouble with the Chinese carbs.
Search Kohler Engines Parts Bulletin 255 for your correct rebuilt kit.
From what you posted I think it's 12 512 03-S, but you must know if it's a Command or Courage engine.

[acscolo]

Oh yes I forgot a few things after rebuilding the carb and before starting
Gas has probably migrated into the oil and diluted it. So change the oil.
Next put a shut off between the fuel filter and gas tank and shut the fuel off after each use.
Last view this YouTube video and rebuilding your carb
https://www.youtube.com/watch?v=5JOgUxBU3MQ&t=1356s
cheers
R

[acscolo]

Bob I sent you a PM concerning Kohler PB 255

[38racing]

Does carb have an antibackfire solenoid?

[Skywatcher]

Hi Bob

Last year a customer brought in a lawn tractor with a Kohler Command-15 that displayed similar symptoms to what you are describing. The base problem turned out to be a badly worn intake lobe on the camshaft. The intake valve simply wasn't opening enough to draw in sufficient fuel/air mix for the engine to run. If you run out of other checks and tests and still can't get the engine to run, remove the valve cover and sparkplug, then turn the flywheel by hand and watch the rocker action to see if both valves are moving the same amount. Not saying this is your problem this time, but it might be worth checking into. All the best

William

[KE4AVB]

Yes worn cam lobe(s) are possible; although, rare. I just had my second one in ten years. First was on a v-twin and now an exhaust lobe on the troublesome 793880 cam. Boy what a weird running engine and after cleaning the dirty it wold only start and die. I notice backfiring through the intake so I went to check the valve, barely any lift on the exhaust.

Anyway that mini ZTR, I say that as it is a 34" was a pain to get the engine off. from stuck PTO clutch to two engine only accessible by wrench and only turned 1/12 to 1/16 of a turn when removing them. Oh I could have removed both hydros just didn't want to.

[bob]

Sorry for delay but have busy. I did get it going and I think everything goes back to a cheap ebay carb. I adjusted float which was pointing at more like a 45 degree angle tha level. I pushed the seat farther down which allowed needle to go farther down. I have i now going but still problem with leaking gas. I would never use this carb without a gas shut off. I have also had to do some adjustment to make choke plate open and close properly This is what you get for $16.00 carb and that is CDN price