# Honda GX120



## thumperuk (Nov 3, 2012)

Hello, could anyone give me some ideas please.I have a Honda GX120 engine running a table saw for logging.Last week it would start ok then stop after about a minute.If i left it for about 5 minutes it would start for about 20 seconds then stop.It does not race,just runs fine then stops.
I stripped and cleaned and rebuilt carb.Cleanead out tank a fuel line.Put clean fuel in with treatment as suggested in other posts and when i put it back together it was exactly the same.
I thought the carb itself had a problem so i bought a brand new one,re cleaned tank and fresh fuel. Still exactly the same.Runs for about a minute then stops.I thought it was using fuel from carb bowl and then being starved from tank,but if i take out bowl blead nut on carb fuel is free flowing and constant.
Any ideas please?:smile:


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## Basementgeek (Feb 7, 2005)

Hi and welcome to TSF

Try running with the gas cap loose. May have a clogged air vent on the tank.

BG


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## thumperuk (Nov 3, 2012)

Thanks for reply Basementgeek. 
I tried that before and after fitting new carb. But i have also tried it again today just to make sure. Still same problem. Its annoying as it starts first pull,sounds sweet,then just dies. Bit loath to throw engine and i realy nead my saw. I,m usually pretty good with engines,re build Polaris,s as a hobby.I will see if i get any more suggestions before i do anything to hasty.
Cheers.


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## Basementgeek (Feb 7, 2005)

I take it that is does not have a fuel pump.

BG


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## thumperuk (Nov 3, 2012)

Hello and thank you again. No gravity feed from tank above engine. Only about 6“ of fuel line between tank and carb. Have alo taken this of and put air line through.


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## Basementgeek (Feb 7, 2005)

Right now I can't think of a thing, sure sounds like a fuel delivery problem.

You did replace the gasket between the intake pipe and the carb, right?

Does it have a primer button or a choke? If it is choke, try leaving the choke part of the way on.

BG


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## thumperuk (Nov 3, 2012)

Hello again Basementgeek,
I did not replace gasket with a new one i just put old one back on. I will order up a new one and try that(never thought about that).
It does have a choke but once started very quickly have to take it off.If i try to put it even half way on the engine splutters,any more and it dies.
It will take a couple of days to get gasket here but i will update when i have tried.
Bit held up a the moment also,had water pipe burst flooding half my house before it was found(middle of night).So under orders to get it cleaned up before allowed in workshop.


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## Basementgeek (Feb 7, 2005)

The gasket would be a real long shot, but they should replace every time you pull a carb, per the book. I don't always, I coat them with liquid gasket material.

Try less than 1/2 choke.

I don't think valves are what is giving you your problem but have you ever checked their settings ?

How does the spark plug look? Is it wet looking ?

Guess I am just taking guesses here because right now I am out of ideas.

Good luck on water line break.

BG


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