2007 Honda foreman 500 4x4 es smoking

[Gwbarm]

So there is excessive oil getting in the cylinder or the oil ring is not doing its job, the only job the oil ring has is to wipe the excess oil from the cylinder, synthetic oil makes this job harder, i have had engines start burning oil after switching to synthetic, so it is possible the ring is not springing out like it should. 

Do you have any oil pooling in your air box, and what does the plug look like tan or black.

What i would do, unless it is smoking excessively, as long as it is running good and no noises, i would run it and see if it gets better or worse. 

[jen]

Great Job Jeff sticking with your problem...I wonder if you can just pull the Jug (Guys like to call the cylinders Jugs.   LOL.) .pull the Jug off just enough to inspect the oil ring...it's the bottom ring on the piston.

Remember if you pull piston out you will need a "ring compressor " tool to put rings and piston back in.😘

[jen]

BTW  Gwbarm will know if I am correct about the oil seal o ring inspection..

AND if you cycled the motor with the spark plug out did it blow oil??Just wondering for my own information.

[Ejwill]

No it did not blow oil out. And the spark  plug didn’t hav wet oil on it.

[Ejwill]

9 hours ago, Gwbarm said:

So there is excessive oil getting in the cylinder or the oil ring is not doing its job, the only job the oil ring has is to wipe the excess oil from the cylinder, synthetic oil makes this job harder, i have had engines start burning oil after switching to synthetic, so it is possible the ring is not springing out like it should. 

Do you have any oil pooling in your air box, and what does the plug look like tan or black.

What i would do, unless it is smoking excessively, as long as it is running good and no noises, i would run it and see if it gets better or worse. 

I got my battery charged back up to 13.4 and I did compression test looks like it went to 170. I guess it makes a difference with my a battery being fully charged. There is no oil pooling in the air filter box. The plug is black but does not have a heavy carbon buildup on it.

[Ejwill]

I got the batter to finally get a full charge No it did not blow oil out. And the spark  plug didn’t hav wet oil on it.

[Ejwill]

9 hours ago, Gwbarm said:

So there is excessive oil getting in the cylinder or the oil ring is not doing its job, the only job the oil ring has is to wipe the excess oil from the cylinder, synthetic oil makes this job harder, i have had engines start burning oil after switching to synthetic, so it is possible the ring is not springing out like it should. 

Do you have any oil pooling in your air box, and what does the plug look like tan or black.

What i would do, unless it is smoking excessively, as long as it is running good and no noises, i would run it and see if it gets better or worse. 

I checked the battery and it’s  finally up to full load 13.4. I tried the compression test it went to 170 I guess a fully charged battery makes a big difference. Good for someone following this to remember.

[Ejwill]

 

switch.

 

The. full charge must make a big difference. I had left the switch on and battery had dropped so I put the charger on it got 13.4 that’s when the test went up to 170.

[Ejwill]

6 hours ago, jen said:

Great Job Jeff sticking with your problem...I wonder if you can just pull the Jug (Guys like to call the cylinders Jugs.   LOL.) .pull the Jug off just enough to inspect the oil ring...it's the bottom ring on the piston.

Remember if you pull piston out you will need a "ring compressor " tool to put rings and piston back in.😘

Thanks Jen, I had much rather pull a jug than a cylinder.

[jen]

LOL..   

[Mech]

Just got online after an age and a I'm bit behind things, but, cut from a message with Ej, and because white smoke is something I've seen from time to time..

"Hello Ej. I just popped in after a prolonged spell of acute back pain, from which I'm still not cured.

I can't remember exactly which model you have or whether it's water cooled or not. Steam though usually can't be seen once the entire exhaust has got warmed up, it stays in the hot exhaust gasses without condensing into the cool air as visible mist. Smoke on the other hand stays as smoke whether the exhaust is hot or not.

If it is smoke, check the oil isn't over filled, and check the crankcase isn't pressurising because of a blocked/pinched breather tube. You can check that easily by running the engine for a few minutes, giving it a few revs, then turning it off and quickly undoing the oil filled cap. If it gives a puff of pressure as it loosens then the breather is likely blocked. If you can take the filler out and run the engine without it spitting oil out the hole, then do that for a while, you could put a rag over the filler hole to catch a small bit of spitting, and see if the smoke starts to ease off. It may smoke for a while if there is oil in the exhaust, but if it's not being splashed and pressurised up into the combustion chamber and being burnt, the a lot of the smoking should stop within minutes.

If the breather's ok, and it's really pouring out clouds of white, and I mean particularly white rather than the usual slightly blue tinge, Then it could be that your oil is contaminated with an oil of the wrong type.. There are certain common oils that sometimes get confused for engine oil when there are several containers sitting around.. Haha.. I've seen it a few times. Chainbar oil for the chainsaw is a common one, and it will fill your yard with smoke if someone changes the engine oil for chainbar oil. Transmission fluid is probably the second most common and that makes a lot of white smoke too.

Hope that helps. I hope to be back in the forum soon but I'm not quite ready yet. Catch you when I do.

Cheers, Mech.".

[Gwbarm]

I think i would wait on pulling anything until we are sure what is causing it. Could you post a video of it running so we can see how much and color of smoke its putting out.

[jen]

That was interesting about pressurized crank case.   HMMM 

[jen]

Hope MECH  is better....Back pain  OMG...  THey say it's worse than childbirth. I wouldn't know about either.

  Of course the model ES Jeff has is the air cooled four stroke w OHV.  

I am sure jeff doe not want to pull the motor (Jug) apart.  So a video is great idea.

[Ejwill]

I did what mech said I took the oil filler out put a rag over it and some plastic under it. I was standing up and thought it had started raining, the rag came off And now I’m slick as owl do,do. By the time I wiped the plastics off they looked new. Got to soak my shirt in something to get oil out. But anyway it kept smoking with the filler open. If I can get the oil off my phone enough I’ll try and get a video of th smoking it’s coming out the exhaust and somewhere around the front of the motor can’t tell exactly where it’s coming from. Jen I don’t know about child brith either.

[Ejwill]

I did what mech said I took the oil filler out put a rag over it and some plastic under it. I was standing up and thought it had started raining, the rag came off And now I’m slick as owl do,do. By the time I wiped the plastics off they looked new. Got to soak my shirt in something to get oil out. But anyway it kept smoking with the filler open. If I can get the oil off my phone enough I’ll try and get a video of th smoking it’s coming out the exhaust and somewhere around the front of the motor can’t tell exactly where it’s coming from. Jen I don’t know about child brith either.

[Gwbarm]

It does sound like you are building pressure down there, i would expect a little but not that much, check to see if your vent line is plugged.

[Ejwill]

The smoke out the exhaust wouldn’t show up on a video but there was some coming from somewhere on the front of the motor. It was bluish grey. Don’t know where exactly it’s coming from I wasn’t sure if it could be coming from an exhaust leak or not. Some of the oil was burning off the engine on the back too but it was from the oil shower I gave it. That on the front was doing it before the oil bath. I’ll try on the vent line not really sure where it is. Sorry.

[Gwbarm]

The crank case vent is located below the air filter, it is the metal tube that runs from the air box down to the crank case at a 45 degree angle. Im not sure if the model im remembering is exactly your model but it should be close. The engine smoke could be from an exhaust leak or something else , may need to look at that closer.

[Ejwill]

Ok, I figured out which line it was I took it loose at the crankcase it is the metal line going to the air filter box. I wasn’t sure how to check it but I blew some compressed air through it and it was open. Do I need to check it any other way. While I had the hose loose at the crankcase case I held a clean white cloth up to the crankcase outlet and reved the engine no oil came out when I did that. Don’t know if that means anything or not.

Edited July 6, 2025 by Ejwill

[Gwbarm]

I would stick a wire down the port or blow through it ti make sure its not clogged.

[Ejwill]

Ok I did that and also held a clean white cloth up to the crankcase outlet and reved the engine and no oil came out of the crankcase.

[Ejwill]

Could the carb be causing it to smoke, just wondering what it could be.

[Cj Winds]

Most likely the oil ring. You should rebuild top end, bore cylinder and use bigger piston.

[jen]

Do you know where Jeff can get a kit  for that?

[Cj Winds]

Namura kits are cheap and work fine. You will want to rip apart the engine before you purchase parts. Measure the cylinder and check the head/valves for leaks

[Mech]

Haha.. Sorry about that Ej.Some bikes don't splash oil out the filler, and others  do.. I did say if it could be done without splashing I think.. But should have worned you better..

And, After my post I realised there are some obvious differences between smoke and steam that I'd notice them without even thinking..  Steam smells like steam ouf of the kettle, smoke smells like burnt oil.. Too simple.

I also remembered that white smoke can be caused by the exhaust valve letting oil down into the hot gasses' and hot exhaust' so the oil evaporates, just like water does, and the oil makes white steam if it's not burnt.. It smells like oil.. (we gotta use all our senses, even taste sometimes..haha.).

I think I might have suggested the exhaust valve might be loose or worn months ago..  I suggested that to someone..  Anyway, sniff the smoke, it will be either burnt oil or evaporated oil smell..Burnt oil leaves a trace of blue and un-burnt oil looks white like steam, but it hangs in the air longer than steam..

Hope that helps diagnose it. Keep us posted and we might be able to tell if it's rings or valve or pressurising.. Though if you ran it with the vent hose off, and there was a steady stream of air coming out of the crankcase, then it's probably not pressurising. You could put your finger on the crank vent fitting and see if pressure builds up much, and/or if it starts smoking worse after a few minutes.

Edited July 7, 2025 by Mech

[jen]

Whew!!!  heavy info

[Mech]

#44  Thanks Jen... Haven't had a baby either, but it doesn't take three months to deliver so I think I might be getting the worse deal.. 

[jen]

Seriously, i hoe you recover.  i cannot imagine the pain. 

 Good info however.....  Probably a lot of people learned a lot from Jeffs problem as it unraveled during  this Post. I know I did.