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I have a 16HP Kohler command on a ride on mower it's fitted with an LMK Walbro carb. Won't start without starting fluid. Runs like a clock on its own after a quick squirt of starting fluid.
Here are the facts! Has good compression, Has good strong consistent spark "Tested with 2 forms of spark tester", Has not sheared or moved the crank key, Has had new impulse fuel pump fitted and tested OK, Fuel shut off solenoid removed, Carb removed twice and totally cleaned thoroughly including idle circuit behind welsh plug, replaced steel fuel crossover line which was rusted inside and out all new rubber fuel lines replaced, New spark plug fitted, Battery at full charged volts and cranking speed is good, there was a lot of play in the throttle shaft which I have since re-bushed I manufactured some in my lathe, Fuel is fresh, Carb float appears to be OK, Float needle appears OK, I am fresh out of diagnostic ideas. Regards Alan

Profanity was surely invented for those working on small engines

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If it won't start either pilot circuit needs attention or the choke is not working. You've talked about everything else but the choke.

Back to the basics = air, fuel, spark and compression.

Did you pressure test the carb needle and seat?

Carb float height parallel to the bowl mounting flange?

Ever check the valves, on the PROPER stroke?

Check for vacuum leaks?

Do you have enough spark to actually fire a plug, inside an engine? Not just I see a spark and call it good?

Thanks Slomo! I appreciate your feedback

As I only recently acquired this machine I have worked my way through it and replaced all suspect components and yes I took off the shroud and degreased and cleaned all that inaccessible area the fuel float is parallel, the choke butterfly is working, I have not checked for vacuum leaks yet but as far as the valves go it runs perfectly when given a start on starting fluid so I am 99% sure its fuel related, I also have a spark resistance tester and it has a very robust blue spark. As you suggest I will pressure test the needle and seat I have a manometer so I will check for leak down etc.

Thanks once again for your response

Regards
Alan

Hello!
Current update! after closer inspection the choke butterfly was not totally closed in the operating position a quick cable adjustment and "Kapow" it fired thank Slomo its nearly always the fundamentals that get you
Your advise sent me back to a more diligent diagnostic path thanks again for taking the time to help

Best regards
Alan

Profanity was surely invented for those working on small engines

Click to expand...