Tons of smoke! Help

[84HONDA_ATC125m]

I got a 1985 atc 125m, one day it started smoking, thick white smoke. I changed oil, flushed fuel system and ran fresh clean gas in it, still smokes like crazy. I ran a compression test and everything came back fine. My plugs are fowling, but it is not burning a noticeable amount of oil. I checked the timing and all, everything was good. I went to check the valve clearance today, at TDC the valves will jiggle left and right, rather than up and down, is this normal? Could bad valve seals be my problem, how would I know for sure? It smokes all the time, smokes more with higher RPM's. It will idle perfectly and run great, but it smokes a ton. Any help would be greatly appreciated.

[swampthang]

How much compression does it have?

[Chazz of Blades]

My 200S has started doing the same thing. It was smoking a bit of blue oil smoke for a while, then one day started POURING white smoke, which smells strongly of oil, but it's barely burning any oil at all. Runs fine, starts fine, idles fine, and compression is good on it.

[tri again]

oh? so it sounds/smells more like it may be 'vaporizing' oil, than burning it? maybe?

Sucking fresh oil thru a valve seal?
Do they even have valve seals?

Did the kids help you wash it and stick the hose in the exhaust?

and yes, 84H, you may want to make sure your valve lash is correct.
Free manuals in the 'world class help' section.
and I may be wrong, but crank tdc comes around 2x as often as cam tdc.

Whatever the manual says is best to follow.
I think I forget more than I ever knew sometimes.

[84HONDA_ATC125m]

Ok thanks for the help guys. Still pours out smoke! The manual says that 175 plus or minus 22psi is normal compression, I am at about 152psi right now. I am beginning to think it may be the piston rings. It was ran through tons of water before it started smoking, maybe it is rings AND valve seals? Plugs keep fowling and it wants to stall when you give it gas.

[Texaskev]

Just a thought......you said ran thru "tons" of water before started smoking. Water in the airbox? Tank? maybe both? might still run.........

[just ben]

Ok thanks for the help guys. Still pours out smoke! The manual says that 175 plus or minus 22psi is normal compression, I am at about 152psi right now. I am beginning to think it may be the piston rings. It was ran through tons of water before it started smoking, maybe it is rings AND valve seals? Plugs keep fowling and it wants to stall when you give it gas. whats 152+22=?

[fabiodriven]

Run through tons of water.... Tons of white smoke.... C'mon guys. This ain't rocket science.

Why has nobody suggested a muffler with water in it? If that is the case it's just gotta cook out, no big deal. Does the smoke smell like oil? Is it just steam?

[84HONDA_ATC125m]

I have switched mufflers with a different bike (exact model), still smokes like heck, I already flushed the fuel system, cleaned and dried the air filter and box. I am running 2 psi below bare minimum. I am getting a strong feeling it is the piston rings, if I try and replace them don't I have to hone the cylinder? If it isn't gouged or scratched too badly, can I just get away with fresh rings? I don't have a honing kit.If you stick your finger in the back of the exhaust, it comes out covered in a black, burnt oil looking liquid. Probably rings. And to fabio, it does smell like burnt oil to a degree, but not the most potent smell of burnt oil.

[just ben]

I have switched mufflers with a different bike (exact model), still smokes like heck, I already flushed the fuel system, cleaned and dried the air filter and box. I am running 2 psi below bare minimum. I am getting a strong feeling it is the piston rings, if I try and replace them don't I have to hone the cylinder? If it isn't gouged or scratched too badly, can I just get away with fresh rings? I don't have a honing kit.If you stick your finger in the back of the exhaust, it comes out covered in a black, burnt oil looking liquid. Probably rings. And to fabio, it does smell like burnt oil to a degree, but not the most potent smell of burnt oil. I would do a hone at the very least.even if the clylinder looks good. the purpose is not only to remove fine scratches but to deglaze the bore. you pretty much have to tear it down to see how far you need to go with it.

[84HONDA_ATC125m]

I know how a hone works, do I have to get a specialized kit for this particular piston, or is it a "one size fits all" deal?

[just ben]

it will run you 25 bucks for a hone or 15.00 to take it to an engine shop and have it done right

[1984 honda 200s]

^^ well thats dirt cheap, i got a quote for my 200s, 65 to bore/hone or 250 for everything ( bore/hone, Weisco piston+rings and gaskets).... Too pricey do you think ?
And for your bike smoking, it sounds like it chit a ring, i would tear into it, mine does the same thing, it wouldnt smoke but you could smell burning oil and it would foul pluggs. I would tear into it and get a quote for a fresh top end, go with a bore/hone and the next over size piston to your cyl. If you do decide this i would make it a Weisco 200x piston. This could save you money in the long run, im eventually tearing into mine AGAIN, im sick if toping up the oil everytime i take it out, $4.50 a quart of 10w/40 or 10$ for 5L of 20w/50, one quart lasts me a week.

[just ben]

^^ well thats dirt cheap, i got a quote for my 200s, 65 to bore/hone or 250 for everything ( bore/hone, Weisco piston+rings and gaskets).... Too pricey do you think ?
And for your bike smoking, it sounds like it chit a ring, i would tear into it, mine does the same thing, it wouldnt smoke but you could smell burning oil and it would foul pluggs. I would tear into it and get a quote for a fresh top end, go with a bore/hone and the next over size piston to your cyl. If you do decide this i would make it a Weisco 200x piston. This could save you money in the long run, im eventually tearing into mine AGAIN, im sick if toping up the oil everytime i take it out, $4.50 a quart of 10w/40 or 10$ for 5L of 20w/50, one quart lasts me a week.yeah that would be dirt cheap for a bore/hone but when you take the bore part out of it,it's pretty much an average price

[1984 honda 200s]

Yeah honeing is pretty cheap, but the way it sounds, he might need to bore it out maybe just .10 over will do the trick depending if its scrored bad or not, a few light scratches will be fixed with a simple hone, not sure if it would stop the smoking part, it didnt for mine..

[oscarmayer]

if you pull the jug, you may as well repalce the pisotn and bore/hone to the next size. it's not worth the $ to jsut half ass the repair and do a hone/rings as when you hone it (it's alreayd worn) you will remvoe even more maerial causing the rings not to seal as well and will soone rthan later start smoking again. hint hint. so do it right and just get a new larger piston kit and get it the jug bored/honed to match. it costs me $60 for a bore/hone job here. before you order the piston, take the top end appart and measure the jug. you need to get the correct sized piston. i hagve found quite a few times where someone put a smalle rpiston into a larger jug for some odd reason. so get the correct stuff.