View Full Version : Honda GX240, Starts won't run ?


robvan
10-19-2008, 10:45 AM
Anyone got an idea or ? Already had a Brigs that blew up......

Honda GX240 8hp Genenator, Kodiak Brand 4000w. A bit worn out, ex rental unit, Burns oil,

Was sitting for over a year and only used once in a while previously, before now, last time it ran was having a problem with it only running a short time before quiting, 15 minutes or so, Thought it was from a leaking fuel line when warmed up and never got around to fixing it till now,, also had previous problems with excess water somehow getting in the gas, condensation, and used to always have to drain the float bowl and fuel valve bowl before it would run any length of time and once replaced all the fuel and cleaned the tank.
Sits outside, undercover on the roof of a converted school bus motor home, Pacific NW, wet coast.

This time it sitting so long the gas had gelled, Intake in the tank and fuel shut off valve clogged,
Pulled the Tank intake tube/screen out, Rinsed out the tank, put new fuel in, took the fuel shut off valve apart, (which isn't made to be serviced) and cleaned it, and put it back together, took the carb apart and blew out the passages as best as possible,

Engine starts but won't run for more than a few seconds, So pulled the carb off again as suggested in another post with similar problem and cleaned the emulsion main jet tube which had some partially clogged holes, also shortened the fuel line to fix the previously noticed minor leak, (an inline filter eventually installed seeing the original in tank one no longer there and relying on the valve screen now) and still have the same problem.

It noticed when starting with the choke on, that it automatically opens or the mechanism moves after it starts and thought to be normal, Tried to get my fingers in there to stop it and may have been able to get it run and second or two longer. It hard to get at immediately after starting, But don't think that's the problem, Also tried manipulating the throttle rod and that also making little difference.

This carburetor (Keihin) also has some kind electric solenoid in the base of the float bowl that I have no idea what the function of is, A white synthetic material pin extends up from it into the main jet base and may be deteriorated.
The Idle Screw? On the inner mounting flange was adjusted to near closed or is near it now. Thought wasn't quite tight when I went to see how far adjusted out it was and thought I put it back to the same place, just a crack open.
No signs of muck on it when removed and passage seemed clear when blown into.
Also has some kind of black plastic item that sits on top of the carb that is held in place with a large black plastic screw that sits laterally on top of it or holds it in place, but doesn't look like it adjusts anything. Thought that it might be a cam of some sort, but on closer inspection appears to round and the 2 items appear to not have any mechinical function.

I might try taking it apart again and blowing it out with more cleaners and air, Trying to get into the emulsion tube circuit,
But in the mean time, someone out there doesn't happen to have a schematic of the carb (20B B MC7 on the flange, BE on the casting and 160 on the throttle plate) and or service info on this application they'd be willing to pass on or know where one might be found?
Generator, a bit more complex in operation than most gas power units, The PDF manuals found for this type of engine so far in my searches offer nothing useful, Unless I could afford to pay someone else to work on it.

Thanks in advance....

robvan
10-19-2008, 09:20 PM
I cleaned the carb a bit more thorough, Presume that solinoid is for the fuel shut off and the black plastic items some kind of plug tied into the top of the main jet curcuit and the screw over top of it and holds it in, the throttle adustment, (adjusted 2 1/2 turns out) Blew out all the passages with carb cleaner, everything looked good except.....
This time on closer inspection noticed the main jet still had crud in it,
I previously presumed it was ok, able to see light through it and blew it out with carb cleaner. But close looking with an magnifying glass, see it was clogged with some kind of build up about 75%, Scraped it out with a needle, When all together, Started second pull, After a bit of smoke, cleaning up after a few minutes, Now running good.
Reconnected the low oil shut off, that having been suggested a problem sometimes.