OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Honda Engines Non starting GXV140 - logic check please

Hi folks, I need some suggestions where to look next.

Brief history
Mower worked when first bought but seized after first use. Dismantled and found big end seized. Fixed that. Piston bore looks good no visibly worn parts inside. Lapped valves reassembled. new plug. Non -starting.
Adjusted choke as suggested. Non start. Carburettor replaced. Non start.
If I drop a bit of petrol in inlet manifold it starts easily until petrol used up.
By "non start" I mean does not fire at all after many pulls in any throttle position - completely dead.

Fuel line ok.
Fuel in carburettor bowl.
With carb remove you can feel suction when crank turned.
Spark at plug. Not particularly strong spark but runs with fuel dump.
Engine stop cables/switch disconnected.
Valve clearances checked & re checked.
Some compression. Can't measure but reasonable resistance to turning crank. Thumb over spark plug hole feels pressure.
Next check is to drain fuel completely and put in new fresh shiny petrol.

If the ignition was poor I would expect to hear the occasional misfire when turning.
If it were a carburettor problem I would have expected some difference when it was replaced. All gaskets and spacers look fine and I checked they are in the right places and the right way round.

If anyone has any suggestions where to look next or checks I can do to narrow down the problem it would be greatly appreciated.

I'm all out of ideas and I don't want to start buy lots of replacement parts as the mower has been a bad buy already.

Engine details GXV140 & GJAB-8054370 on crank case. ZG9 on piston head case.

Hi Duncan, you have given yourself the answer, the carby is the problem, just the fact you can put fuel in the inlet and it will run proves that. The Honda carby is a bitch because of the way they used bolts instead of studs (as per the Chondas) and you have to get the spacer and heat shield all together at once and the right way around. The other problem can be with the new carby, some just won't work, it is a real crap shoot. Is the choke butterfly fully closing?

Also make sure you are using the right carburetor for the particular type number you have. In the area you the the serial number there should be some letters and numbers. THere is about 40 different types in the GXV140 range using various carburetors configs.

So if you can post the type number I see if can find out the Honda part number for the correct carburetor.

I've been very confused by the variety of types but haven't found a way to tell which type it is. I'm based in the UK so presume the motor was a European model. It also seems odd that the engine number is above the range most parts website say exist.

Choke was closing fully. The odd thing was that the motor was running quite well when I used it. That suggests that either I've put something back wrong (I didn't take out the timing gears) or something I've done has messed it up. I cleaned the old carb thoroughly and didn't find any blockages in any of the jets or tubes.

I'll have another go when the stress levels have dropped.

The odd thing was that the motor was running quite well when I used it. That suggests that either I've put something back wrong (I didn't take out the timing gears) or something I've done has messed it up

Duncan, the fact you say it ran quite well means stop thinking along these lines, the problem is the carby, the rest of the rebuild is fine by the sound of it, fix the carby and you will fix the problem and I have found that cleaning the old carby doesn't always work either. I don't have an ultrasonic cleaner so I can't say if that would fix the problem. Another little trick is to get some 6mm threaded rod to make up studs for the carby so you can assemble all the bits without putting the filter housing on and then you can see that everything is working and the choke is closing fully. Then you can put the filter housing on after you have got it running. The way Honda set these up is just an abomination, something that Briggs got right with their Quantam carby bolt on method.

I took the new carb off and gave it a check and clean. New fuel and blew out all hoses.
I'm not sure the pilot jet went back in the exactly the same place but it runs.
Thanks so much for your help.

I'll need to set up the governor and idle adjustments as it is running fast at present. I think I saw another post on that subject. Thanks again.

Hi Norm,
You're thinking of the GCV motor with the awkward carby mount setup. This is a GXV, which is set up exactly like a Chonda.
Cheers, Ted