2007 Honda foreman 500 4x4 es smoking

[Ejwill]

My 2007 trx500fe is smoking at Idle and while running through the gears. It’s white to grey smoke not black. Give me the bad news like top end rebuild or something. I know it can’t be something easy. Any help will be appreciated.

[jen]

They have some really smart guys here...Me I can only look at my experience//I would look at coolant being low to point to water getting into combustion chamber.  Look at oil...Is it milky brown showing water in oil?

Compression test would be interesting..

Does it run strong or erratic?

Oh my I feel for you...

[Gwbarm]

I agree with Jen typically white smoke is water getting into the combustion chamber, usually from a blown head gasket.

[jen]

I am not a fan of Honda's, albeit their motors are legendarily tough and well built.  They don't fail often.

How did your problem happen?   Motor ran HOT?  I would want to know after replacing the head gasket ...planning the head for flatness etc.

  A friend of mine.....well ex friend I probably, Hà ha,.... managed an upscale golf course.  They only ran Non-ethanol fuel in all the golf course equipment.  He said it reduced motor failures and fuel related maintenance problems.   He said the Non-ethanol fuel was 95 octane and reduced "pre-detonation"...I called it pinging.

[Ejwill]

I just bought it not long ago. Changed oil and filter, replaced air filter. To be honest I Thought it was just air cooled. No idea about water reservoir or anything water. Dummy me. The manual I have doesn’t mention anything about water coolant. Are you serious or is this like sending the new guy to tool room to get a left hand monkey wrench. Where would I find the reservoir. Dang thing might be out as far as I know.

[jen]

There are some good 'You tube videos on 500 Honda Foremen coolant  inspection / maintenance.  Check those out.  

I could not find anything under Problems with the 2007 500 foreman having a systemic smoking problem problem. 

 I am sure that is a nice machine  manual transmission  I believe .

[Ejwill]

It’s es 4x4. I’ve tried u tube. Didn’t find anything on the coolant reservoir or adding coolant. I have a manual and it doesn’t have it in there either. Can’t locate a reservoir or radiator have an oil cooler but nothing on water coolant for my 2007 Honda foreman 500 es 4x4.

[jen]

What is the exact model?   I was looking at the 2007 Honda 500 foreman.  That is what was on a heading.  

[jen]

OK  found ES midel..it is carburaated  air cooled.

The main complaints with smoking are:

1 water in the exhaust manifold which will clear up .

2. Carburetor mis adjustment

One complaint had white smoke and after a while oil coming out of Muffler.

[jen]

There are several smoking issues documented.  Fortunately they were solved with a rebuild.  Honda Foreman website.

Good luck...

[Ejwill]

I was hoping it was the choke but wasn’t. I don’t know what to try next except top end job. Nothing has changed in the carb. Before it was not smoking. Smokes really bad if I rev it up when in neutral, as well as when just riding. Seems worse when I rev it up in neutral. Any ideas where to go from here.

[Gwbarm]

Hondas are tough engines i was avoiding going there because i very rarely see one with a roached engine, but not knowing the history or abuse level it could be possible.

Have you done a compression check, i would do one, see what the readings are then put some oil in the cylinder not a lot maybe a couple of tablespoons, do another compression check, if the compression goes up the rings are bad. It could also be smoking through the valve guide seals, it could be a combination. How many miles are showing on it.

[jen]

Is there oil on the spark plug when yo shut down and remove plug?

What mixture of fuel are you using?

Does it have normal power and acceleration?

[Maddman200]

From the sounds of it, it's burning oil. Possible causes piston ring wear or valve seals are leaking. Hope this helps with the start of diagnosing your issue

[Ejwill]

It does help and I appreciate it. Looks like I may have to go ahead and check the valve seats and the rings.

[Ejwill]

1 hour ago, Gwbarm said:

Hondas are tough engines i was avoiding going there because i very rarely see one with a roached engine, but not knowing the history or abuse level it could be possible.

Have you done a compression check, i would do one, see what the readings are then put some oil in the cylinder not a lot maybe a couple of tablespoons, do another compression check, if the compression goes up the rings are bad. It could also be smoking through the valve guide seals, it could be a combination. How many miles are showing on it.

I don’t know how badly it was treated before I got it but the guy I got it from wasn’t a very trustworthy person. It had some problems that shouldn’t have been there, stripped nut on the clutch adjustment, I don’t know how he did that, the seat wasn’t the right one for this wheeler. I had to grind some off of the prongs to get it to lock under the metal rods. I had to replace the oil thermostat . The middle and rear skid plates are missing. So I don’t know what else may be wrong. The odometer reading was 4668 miles and it’s a 2007 model. I took the spark plug out as I was servicing it. It looked good no fresh oil and didn’t have a lot of carbon buildup on it , I changed it anyway. Can you rent compression testers or do I need to go ahead and buy one? Probably something I’ll be needing down the road anyway. Think of any thing else, or is that mileage enough to draw a rebuild? Thanks for the help. Oh I almost forgot the acceleration is good couldn’t open it up to much just going around the house. But I got it up into 5th gear. Thanks again.

[jen]

Auto zone and other auto parts stores may have free ones to use.

[Gwbarm]

In #11 you said before it wasnt smoking at what point did it start smoking. Did anything happen before it started smoking ? 

It does sound like its been ridden hard and previous owner or owners didnt care much about the machine probably used the wrong tool to adjust the clutch and stripped it out, might have taken the plates off to replace the u joints and didnt bother putting them back on. I have seen many in this shape, in fact i usually but them in this condition because i like bringing them back to life.

The milege is not excessive i have seen these with over 15000 miles on them but they were well cared for. No carbon on the plug is good what color is it brown black light tan. What are you running for oil brand and viscocity.

As Jen said you can borrow from autozone for free put up deposite and get it back when you return the tool. I just buy mine around 20.00 on Amazon. Not quite sure good as my Snap-On but work very well.

I dont know how long its been running or sitting but its possible a ring could be stuck and will probably come back after you run it for a while, if its been sitting the more you run it the better it will get. I think i would just run it for a while if its running good no noises and good power. You can also put a little Marvel Mystery oil in the gas to help if it does have a stuck ring, but you can determine this after the compression test.

[Ejwill]

The oil is Honda pro oil 10w30 SJ. And I can think of anything other than sitting for  a while if that could have made it start smoking.when I ride it it’s just around the house a couple of times then park it back in the garage. Against the law to put it in the streets, but yet kids 7-8 yrs. old ride utv’s and golf carts loaded with other little kids ride on the streets all day long. As far as my wheeler it does sit up more than its ridden. I’m going to call auto zone and see if they loan or rent out a tester.

[jen]

Hey ,,...Let us know how it is going. The compression check will tell a lot.  Remember what Gwbarm said to check  compression then add oil and recheck compression.  Good Luck  keep in touch.

[Gwbarm]

That explains it a lot better, i was thinking you may have just got it running for the first time after sitting for years. So you have had it for a while and only run it every few months. That would not cause it to start smoking, what can happen upon initial startup after sitting for a few months is smoking from the valve guide seals but that generally goes away with the first minute of running. If it is not going away could be bad seals. So we will see from the compression check and go from there. When you check compression be sure to have the throttle open. 

[Ejwill]

I got a tester from auto I called and they said sure we’ll fix you right with a loaner. Got there and the guy I was dealing with said they did loan them but they would rent me one , so I said ok. Then he came back and said they didn’t have one. But he could sell me one. I said fine get it for me so I bought one. Any never done this before. Took spark plug out put the wire back on, placed it so it would be grounded put the right adapter on screwed it in them screwed in the metal hose. The battery voltage was 12.5, I turned it over with the throttle fully opened and got a reading on the guage. I attached it below . Manual says 64psi at 380 rpm’s maybe The Rpm’s were off but this gauge read 179. I have pic of the gauge. I don’t have a clue. The gauge has held that for at least 15 minutes if not more.

Edited July 2, 2025 by Ejwill

[jen]

The gauges lock at the highest pressure.  That is why it is not going down.

[Ejwill]

Isn’t that a very high pressure? At least compared to the 64 psi.

[jen]

YEs that is high from what I read.  70+ is in range from what i saw on Honda forums.   cranking motor without spark plug does it blow  out oil.   Maybe there was oil in cyclindre.  Rechec k. Release tge presssure between each check

[Ejwill]

I rechecked it several times. I opened the choke all the way and watched the gauge when I first hit the starter, the pressure jumped all the way to 100psi on the first hit, then it took 2 more jumps to reach the 179. I read on the package the tester came in and it said if it’s way higher than normal it may have carbon build up on the piston head or on the cylinder. I don’t know myself if that’s correct or not or if that would cause smoking.

[jen]

release pressure after each test?

when cranking without plug does any oil blow out? or pieces of carbon?

[Gwbarm]

The 64 PSI stated in the manual is what you expect to see when testing the compression, there is a decompression valve attached to the cam shaft to release compression for ease of starting. It sounds like this is maybe not working. 64 PSI is not even enough for an engine to run. From what i saw on your compression guage i would actually be glad to see that, it means your compression ring is working perfectly. The one thing that might come into play is if the oil ring is malfunctioning letting too much oil into the cylinder which would also cuase high compression along with carbon builup on the piston as your guage instructions stated. That would explain the smoking. The correct pressure i might like to see on a 500 is between 160 to 170, you are not far from that.

I would try this, with the plug out squirt a little carb cleaner down the hole, crank the engine over to blow most of that out, just to clean oil out of the cylinder. Then run your compression check again and see what you get. I would not tear into the engine just yet your compression is fine, good to see that, also means your valves are working as they should.

[Ejwill]

Ok, I’ll do that but I will have to go get some carb cleaner first. I don’t keep a stock on hand but probably should owning a wheeler any way . Instead of atv’s they should have called them Mprus “money pits are us” no matter I enjoy them and I’m getting where I’m learning more and more about them which is a good thing , thanks to all of you on Quad Crazy.

[Ejwill]

Ok, I did like you said and rechecked it . It did come up but to about 153/154. Got a photo. I guess that might be bad news.