GX240? 8hp engine, 4000w generator, Kodiak brand, same as Honda's with the full size fuel tank, 120-240v, 220v, 12 v plugs.

Old retired rental unit, burns a lot of oil, smokes lots on cold start up, Was working good, Had a problem recently with the carb from sitting for a few years with no use, Had to remove the fuel screen, and clean the petcock daily, since fixed that, run daily average 8 hrs since. couple months now.

Recently the engine started to sound labored the last week, still putting out juice as normal, but getting hard starting, Used ether to get it going, (and used to years ago, but haven't had to recently, even in bitter cold) Starting cord shortened up a bit, tonight tried a new plug and didn't get easier, thought to hear a new tone or whine when fired up,

Proceeded to cut up some lumber with a skil saw and gradually within a few minutes lost RPM and all electrical power, engine sounds like it's running about half speed or just above idle, (Idle control doesn't work so don't know for sure) Voltage gauge showing nothing,
Shutting down and restarting a little later with the old plug back in had it running 10v over normal, 120-130?v
within a minute or so gradually loses rpm again, green power light goes out as well a nil on the gauge. Keeps running at the lower RPM. might still sound like it's under load.
Tried playing with the carb linkage to see if I could get it to rev back up, if it a problem with the governor or related, but not doing anything except stalling the engine one way. Haven't tried it again.
Shutting down has it knocking/bucking hard like a car engine with bad gas. Detonating,

Any suggestions on where else to look or start taking it apart. It seems these units this size still commanding high price used to replace it so might be cheaper to fix.
Was thinking it might just need a valve adjustment for the hard starting if not just lost too much compression, While it probably wouldn't hurt don't think that's the problem, (running heavy oil in it with STP to control the oil consumption)

Possible problem with the governor, generator ? Coupling from all the noise shutting down? Or something simple. Reflash the windings? I presume this is a brushless generator so don't know what might be able to serviced in it.

Thanks.

GX240? 8hp engine, 4000w generator, Kodiak brand, same as Honda's with the full size fuel tank, 120-240v, 220v, 12 v plugs.

Old retired rental unit, burns a lot of oil, smokes lots on cold start up, Was working good, Had a problem recently with the carb from sitting for a few years with no use, Had to remove the fuel screen, and clean the petcock daily, since fixed that, run daily average 8 hrs since. couple months now.

Recently the engine started to sound labored the last week, still putting out juice as normal, but getting hard starting, Used ether to get it going, (and used to years ago, but haven't had to recently, even in bitter cold) Starting cord shortened up a bit, tonight tried a new plug and didn't get easier, thought to hear a new tone or whine when fired up,

Proceeded to cut up some lumber with a skil saw and gradually within a few minutes lost RPM and all electrical power, engine sounds like it's running about half speed or just above idle, (Idle control doesn't work so don't know for sure) Voltage gauge showing nothing,
Shutting down and restarting a little later with the old plug back in had it running 10v over normal, 120-130?v
within a minute or so gradually loses rpm again, green power light goes out as well a nil on the gauge. Keeps running at the lower RPM. might still sound like it's under load.
Tried playing with the carb linkage to see if I could get it to rev back up, if it a problem with the governor or related, but not doing anything except stalling the engine one way. Haven't tried it again.
Shutting down has it knocking/bucking hard like a car engine with bad gas. Detonating,

Any suggestions on where else to look or start taking it apart. It seems these units this size still commanding high price used to replace it so might be cheaper to fix.
Was thinking it might just need a valve adjustment for the hard starting if not just lost too much compression, While it probably wouldn't hurt don't think that's the problem, (running heavy oil in it with STP to control the oil consumption)

Possible problem with the governor, generator ? Coupling from all the noise shutting down? Or something simple. Reflash the windings? I presume this is a brushless generator so don't know what might be able to serviced in it.

Thanks.


Sounds like it is starving for fuel. I would look for something in the fuel line, a plugged filter, or if none of the above, rebuild the carb paying special attention to the float setting. If you are running the generator in a cold enviroment, the thicker oil can be causing hard start. If this is an older engin, like 12 years old or more, it could have breaker points for the ignition. If so, you will need to remove the starter housing and then the fly wheel to get to the points. To remove the flywheel, loosen the large nut but do not remove it.
Put a brass or other soft metal rod against the end of the shaft and hit it sharply with a hammer. This will break the taper lock loose on the shaft and fly wheel so you can then remove the nut and slide the fly wheel off. There is a small tin can looking thing under the fly wheel with a spring clip that holds the cover on. Remove the clip to gain access to the points. Remove and clean the points with emery cloth and reinstall them with a .020" gap when the points are on the high spot of the cam lobe on the crank shaft. You may find a buch of oil in here if the crank seal is leaking. Just clean it out and hope for the best. It should take quite a while to get enogh oil leaking back in to cause you any problem. Change the rope back to the original lenght while you have the starter housing off as well. Good luck, hope this helps!

Thanks,

This a later model with the electronic ignition, looks just like current Honda models with the full frame gas tanks usually 2000 watt up,
Don't know how old it is, but had a similar 5000 watt version back in '90. 5 gallon tank, got this one around '01 so don't think it's that old, maybe 10 years or so. has a 3 gallon tank. 13L est. I don't think they've changed much component wise in 20 years. This one replacing a brigs unit that blew up after about 10 hours, ran low on oil and before it ran out of fuel that particular run.
Since I put a screen in the tank, Sticking a rolled up piece of the fuel filler opening screen up in the hole, (It falling apart and not serving it's purpose anymore for keeping dirt out on fill ups and a proper one a special order part locally)
Noticed a lot of finer grit still getting through, But usually stopped by the screen in the petcock bowl, Haven't had the petcock clog up since (2+weeks now) and It took about 3 months before I had to clean the main/needle type jet (no needle slide in this type of Kehin? carb) when it wouldn't run, cleaning the petcock daily, sometimes a couple times through a tank of gas with so much rust in the tank.
I cleaned the petcock and drained the float bowl on the second try. But might have over filled the oil when I checked it or have a sticky float needle that filled the crank case with gas, but that never been a problem in the past,

I couldn't find the specific plug part number, except an NGK BPR6ES mentioned in a parts store that supposedly fits this unit, Ended up putting in a Champion that was supposed to be the replacement plug for the same NGK,
A hotter plug probably better for the oil it consumes, has an unknown Bosch plug in it now and the original plug I got with it. I cleaned it up and put it back in when it quit with the Champion. Which appeared to run rich for the short time it ran. The Bosch appeared to run with good color, though had lots of deposits on it as expected being in it for years and all the oil it burned.

Also don't have any gap measuring tools handy (yet) so don't know how far out it is.

Anyone got any service info on the gen sets and governor set up/function?
Not sure if this is going to be a tapered or keyed shaft.

The hard starting partially due to the shorter pull start cord and had it still start easily sometimes and usually starts easily when warm. Though, again could be as much a problem with valve lash or lack of compression.

"Burns lots of oil, smokes on start-up"
That could indicate a number of problems, but this being a retired rental unit makes me leary of it having been maintained well. Oil consumption can be for a number of reasons, but usually due to a blown head gasket, or worn internals.

Governor set-up shouldn't be necessary unless you moved the arm on the governor shaft.

Almost all generators with the rotor bolted directly to the crank have a taper-fit.

I got this about 7-8 years ago, it was a bargain, but didn't take long before it started to smoke bad on start up, but usually cleared up after a few minutes, Though sometimes still burning a bit blue, relative to what ever oil I happen to put in it top it up, Used for back up power for my live in bus, sits up on the roof in an enclosure, and wasn't used much other than occasionally started in the last 5-6 years and not at all the last 2.
The only problems had with it way back then was water getting in the gas, condensation in this wet climate, and not using it often enough. being pluged into the grid most of the time,
Didn't take long to figure out the water problem, just regularly drained the float bowl, But think the residual in the tank and accumulating rust was clogging the fuel tank inlet, Hence problems with it not running for that long before quitting and hard starting, Used to use ether on it back then also. (and that sometimes problematic, Washed lubrication out of the bore and creates excessive combustion chamber pressure, head gasket problems if not blowing it up)

The 2 years plus sitting had the gas gel etc, Had to take the petcock apart, which is not serviceable, put back together with self tapping screws and JB weld.

Since I cleaned it out and still problems with large chunks of rust clogging the petcock till that was semifixed as previously noted, it running good, usually starting easily, till the latest problem,
Seeing it's not maintaining RPM will look to the engine state of tune, before going further with the generator testing and hope to be able to find a good used one if needed, Expect they're expensive from Honda,
In the mean time bought a new dirt cheap 1300w back up with a 2 year replacement guarantee, I expect to be using for the amount I'm going to use it, but still need a bigger unit for some power tools. and it's nice in the cold to be able to use some electric heaters.

Local classified ads for Hondas still want high prices for good condition runners.

Again not sure how serviceable the generators are, And seen some posts on how to flash the magnets again if thats a problem, But this one still producing power on start up.
It'd be nice to find some more comprehensive service/testing info specific to these.

An oil change and cleaning of the carb will be tried next, maybe check and adjust the valves, might have a problem with the carb gasket also, If the head gasket isn't also blown now from using ether. If that's the case a new piston and rings should be in order.

There are only two types of honda engines that we could be dealing with, either flat head or overhead valve. If overhead valve (gx240, 270, 340, or 390) there are no points. Common problems would be lack of fuel (try spraying ether as it dies), oil alert problem (yellow wire disconnect on right side of block), or heat soak of the coil (no spark when checked after it shuts off).

Flashing the unit only helps to restore residual magnetism to the rotor for purposes of generating power. However rare, it is possible that the end bearing on the rotor may be going out and is creating excessive load. Other than the bearing going out, the gen head should not affect how the motor runs.