# Smoking Honda GX140



## Bob V (Oct 26, 2005)

I recently purchased a used Honda EM2200X generator, which uses the Honda GX140 engine. When I finally go it home and put gas and oil in it to start it, it smoked quite a bit for the first 60 to 120 seconds. Then the smoke clears up and it runs fine. I have started it many times over the last few weeks and every time is the same. It smokes heavily for the first minute or two and then the smoke stops. I can run it for hours and there is no smoke. I can shut it down for several hours and restart it and there is no smoke. But, when I let it sit overnight and start it in the morning it smokes again, but only for a minute or two. I was running 10W-30 Mobil oil and decided to try straight 40 weight to see if would change anything. It actually made it worse...more heavier smoke. The engine has great compression @ 135psi and seems to run fine. I just cannot figure out the smoke issue. By the way, I have checked the oil level many times and even ran the engine with the oil at the lower lever on the dip stick. It made no difference. Oh, I forgot to mention, the smoke is blue oil smoke. I have had engines with bad rings and when they smoke, it is usually when they get hot and they smoke more as they get hotter. This one is just the opposite. Any thoughts or suggestions will be greatly appriciated. I am willing to try anything...Thanks Bob


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## bugman (Aug 12, 2004)

is it new? does it have a warranty? well anyway mobil one is fine, use it myself and its actually weird for a straight 40? to make it worse.......... is it a horizontal or vertical shaft engine?


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## Bob V (Oct 26, 2005)

The generator is used, but looks to have not been used much. The engine is a horizontal shaft. When I pulled the valve cover off the head, the inside of the rocker area is very clean...Any thoughts???


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## bugman (Aug 12, 2004)

no oil in there?... anyway make sure they are set right. i don't know what they are for a honda though, sorry. as for it being used, must've overseen that..... well as for used, how old? it could be a few things, breather not doing right, rings, leaky valve stems.


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## Bob V (Oct 26, 2005)

The engine is probably about 6 years old, but does not look like it has seen a lot of use. I replaced the breather assembly, which is part of the valve cover with no success. I tried to get a new set of valve seals for the Honda GX140 engine, but was surprised when the Honda dealer said that the GX140 does not use valve seals. The engine seems to have great compression so I shy away from thinking it may be rings, but maybe I am wrong. Would worn valve guides create the problem that I seem to be having? It seems that what ever it is, it goes away as soon as the engine develops a little heat. Any suggestions will be greatly appreciated...Bob


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## bugman (Aug 12, 2004)

warn guides could, after a cool down the oil leaks through. maybe someone else will have other ideas. but that sounds like a possibility. be sure to keep a check on the oil though regularly.


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## roperdude91 (Nov 10, 2004)

sounds like my 1988 MMC 3 liter, smokes alot when cold or sits a while, and 20w50 disapears quicker and smokes more than 10w30
the MMC 3 liter SOHC is known for a valve guide problem, the guides are soft, wear quickly, and have no clips to hold them in place, so they fall lower into the head, producing smoke at cold startup and for a few minutes afterwards, and a slight smoke at idle and right off idle, it will also suck some oil through the guides when you rev it really fast, but the valve guides will not cause any difference in compression, they dont let anything out of the cylinder, just oil into them, they end up working more like a check valve
just for kicks, when you rev it quickly, does it give a puff of smoke?
they only let oil through on the highest vacuum point, idle, and right off idle, and sometimes when you gun it
so yeah, i think it might be valve guides
are they clipped in place, or just there, or can you not see them(fallen into the head)


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## bugman (Aug 12, 2004)

roperdude91 said:


> sounds like my 1988 MMC 3 liter, smokes alot when cold or sits a while, and 20w50 disapears quicker and smokes more than 10w30
> the MMC 3 liter SOHC is known for a valve guide problem, the guides are soft, wear quickly, and have no clips to hold them in place, so they fall lower into the head, producing smoke at cold startup and for a few minutes afterwards, and a slight smoke at idle and right off idle, it will also suck some oil through the guides when you rev it really fast, but the valve guides will not cause any difference in compression, they dont let anything out of the cylinder, just oil into them, they end up working more like a check valve
> just for kicks, when you rev it quickly, does it give a puff of smoke?
> they only let oil through on the highest vacuum point, idle, and right off idle, and sometimes when you gun it
> ...


 thats weird for a heavier oil such as 20w-50 to go faster then 10w-30. anyway (Honda dealer said that the GX140 does not use valve seals)


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## grunge (Nov 9, 2005)

i know whats going on,,,,

its your piston rings, the cylender has been worn and oil is bypassing the rings, thus causing it to burn oil when the motor runs for 2 min or so it heats up and the rings expand creating a proper seeeel, its not uncomon, go to the local honda dealer shoule be like 100 bucks if im correct


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