white smoke when hot

[A.Town]

I have a bit of a conundrum with my '05. My bike spews white smoke but only when warm, and the hotter it gets the more it smokes.

My first thought was oil getting past the cylinder rings. I ran a compression test and both cylinders are right at 130 PSI. That means that the rings are ok right, or can they still leak but not cause a drop in compression?

I then moved on to the carbs. Let me start off by saying the carbs are still stock. I pulled them out and cleaned them (left them in carb cleaner overnight and took a nylon brush to them making sure to get all the little holes in the jets and everywhere) and replaced a few o-rings that looked worn. I put it back on and got the same result.

Next I tried the vacuum system. For this I just capped the left carb and gravity fed fuel to the carbs. Same result. 

I am out of ideas. If anyone wants to venture a guess as to what is going on I would appreciate it. 

[Kijona]

Generally speaking white smoke is caused by one of two things. Condensation (not really smoke but steam) and coolant being burned off. Since you obviously don't have any coolant to burn, it's most likely the latter.

Can you confirm it is smoke? Does it linger in the pipe after you shut the bike off?

A video would be helpful.

Edit: Also, for future reference, oil being burned typically produces blue smoke.

[A.Town]

There is definitely some lingering "smoke" when the bike shuts off. To me it looks too heavy to be just steam. I am working on the video now. Thanks for the help.

[iclrag]

From what i know with chain saws and what not the white smoke is impurities being burned off, now this normally happens once in a while and we wait it out, does it keep happening?? i know today (im taking the safety motorcycle course this weekend) just about all the bikes had white smoke (it was raining all day too) which can be attributed to condensation, a common occurance in the great north west

[A.Town]

As far as I can tell the smoke just keeps coming. i ran it for about three minutes once to try and wait it out and the more I ran it the thicker the smoke got. As far as condensation I live in the central valley of California (hot dry desert), and it was about 85 degrees with no humidity when I shot the video.

http://www.youtube.com/watch?v=0XtvXlKeXgk&feature=youtu.be

In the video I know it does not look like a lot of smoke but in person it looks much worse. I let it idle for about 1min (I cut out most of the warm up time not to bore you). Then it started to puff out white smoke like it always does. If you watch to the end you can see white smoke continue to waft out after the engine is shut off. Sorry there is about a 1 second video-audio mismatch. I guess I need better editing software  . I hope this helps 

[Janx101]

I'm no expert on this at all , however the smoke visible still looks to be behaving like steam? I'm probably just sayin nothin here but my initial wondering moment was ..

is there a higher than normal water/moisture content in the fuel? Causing visible vapor even tho you in dry climate?

And does the vapor have a different smell than normal exhaust? If it is burning oil you will notice change in smell

Is someone maybe messing with you and put a contaminant in the fuel?

Even tho you are in dry desert , what's the relative temp and humidity change in the garage? Cooler and moister I would think?

The timing of a up to a min is about the same as condensation appearing in most engines .. Oil smoke usually starts when engines do

Lastly ... How long that carbon can been on? New exhausts can be odd/finicky till they settle in ... And maybe it's just the vid sound but the engine sounds to a little rough and slight miss here and there .. So again is the fuel good and is the tune and jetting right for the can/pipes?

[A.Town]

The bad gas is a possibility, and is easy to check. Thanks for the suggestion. I don't know how I overlooked that.

The pipe was put on by a previous owner and the bike has run well with it in the past. I have also run the bike in colder and even drier months here with with no cloud of "smoke" spewing out the back end.

[Kijona]

Okay, having looked at the video it does in fact appear to be smoke. Steam won't blow around like that and quickly dissipates. It also will not linger inside the pipe after the engine is shut off.

Bad gas is another possibility I too overlooked...however:

I'm concerned about the clanking noise your engine is making. It does not sound like it is running well at all. When was the last time the valves were checked? Another quick thing you can do is (after the engine is completely cool) remove the sparkplugs and have a look at them. Do not remove or insert spark plugs with the motor hot or even warm - the head is more easily damaged/stripped.

A picture of the spark plugs could tell us more. Also, check your oil and see if it smells heavily of gas. Used motor oil tends to have a "burnt matches" smell to it, with a slight hint of gasoline. It should not have an overwhelming smell of gasoline.

Report back and we'll go from there.

From what i know with chain saws and what not the white smoke is impurities being burned off, now this normally happens once in a while and we wait it out, does it keep happening?? i know today (im taking the safety motorcycle course this weekend) just about all the bikes had white smoke (it was raining all day too) which can be attributed to condensation, a common occurance in the great north west

Well, the biggest thing you have to take into consideration is the fact that chainsaw motors are two-cycle and impurities are quite common. The environment chainsaws are exposed to are also much, much harsher than what your average street bike is exposed to.

[A.Town]

Sorry, I forgot to mention that I changed the oil early on as well to try and fix the problem. I thought some gas maybe got washed down in to the oil, but the situation did not improve after the oil change. There is no gas or burned smell from the oil currently. The clanking noise is a new symptom. I thought it was due to lack of gas, but I fired it up again today with lots of fresh gas and it still backfired through the carbs. I will clean the carbs again and check the valves and the timing. All of this was supposedly checked by the last owners mechanic about 300 miles ago but I have recently found out he is not the most trustworthy fellow.   
Here is a pic of the spark plugs.
http://www.flickr.com/photos/81676530@N05/7484794668/in/photostream
the black one was from the cylinder that was backfiring. Hope this helps and thanks again everyone.

[Kijona]

Well neither one of those look horrible.

Perhaps you could try increasing the idle speed a bit?

Have you messed with the mixture needles at all? If so, it's possible you broke one or one is way off kilter.

What kind of shape is the battery in? How old is it?

[Precisi0n]

I'm wondering if it could be a blown head gasket or piston ring.  Might inspect the top end for any visible oil leaks.

How long were the spark plugs run with the smoking issue?  A blown piston ring will foul the spark plug on that side.  One of your plugs is definitely darker than the other.  If you've only run the engine a short time with the smoking issue, it may not have not had a chance to really foul up.

I'm no expert here...just a couple ideas.

Edit: Sorry just saw that you ran a compression test.  Probably not the rings

[bryan88]

Just a thought, it could be the valve stem seals, most noticeable if you coast down a hill then accelerate.

[duffy]

looks like you're burning oil, I agree with the last post, valve seals...

[iclrag]

i just remembered, my dads friend just had to get his engine fixed because the gas he got at a gas station had water in it, hope the same didnt hapen to you! but worth checking

[A.Town]

Update:
When I took the carburetor out and inspected it I did find one of the mixture screws to be a little off. I also checked the valve clearances and one was slightly less than .03mm so I will be replacing that. I also cleaned the spark plugs. I think these will solve the misfire problem but not the smoke. Hopefully I am wrong.

looks like you're burning oil, I agree with the last post, valve seals...

Correct me if I am wrong but wouldn't a bad valve seal smoke a bunch when the engine starts cold? Mine will not smoke until the engine warms up.

i just remembered, my dads friend just had to get his engine fixed because the gas he got at a gas station had water in it, hope the same didnt hapen to you! but worth checking

I will look more into the bad gas. Thanks for the help everyone.

[Kijona]

Update:
When I took the carburetor out and inspected it I did find one of the mixture screws to be a little off. I also checked the valve clearances and one was slightly less than .03mm so I will be replacing that. I also cleaned the spark plugs. I think these will solve the misfire problem but not the smoke. Hopefully I am wrong.

looks like you're burning oil, I agree with the last post, valve seals...

Correct me if I am wrong but wouldn't a bad valve seal smoke a bunch when the engine starts cold? Mine will not smoke until the engine warms up.

i just remembered, my dads friend just had to get his engine fixed because the gas he got at a gas station had water in it, hope the same didnt hapen to you! but worth checking

I will look more into the bad gas. Thanks for the help everyone.

You are correct. I had a KLR650 (1988 model, 7.5k miles on it) that would smoke like hell when cold but then stop once it was warmed up. You're having the opposite effect, and, not to discredit these other folks but oil burning does not usually produce wispy white smoke like that. It's usually heavy blue.

[Janx101]

I'm still keen to know does the vapor have a different smell to normal exhaust?

Like other things on vehicles ... Burnt clutch smell different to hot brake to gear oil to blown rings oil to radiator etc etc etc .. A mechanic that knows should be able to at least smell the vapor and narrow it down for ya ......

The nose knows bro's !

[Twisted]

I'm still keen to know does the vapor have a different smell to normal exhaust?

Like other things on vehicles ... Burnt clutch smell different to hot brake to gear oil to blown rings oil to radiator etc etc etc .. A mechanic that knows should be able to at least smell the vapor and narrow it down for ya ......

The nose knows bro's !

Agreed. Oil smoke has a pretty unmistakeable odour. A bike running rich gives off smoke too but that would cause a dark smoke not white.

[jacob_ns]

That engine doesn't sound healthy.

[mister]

That bike is sick. I don't mean "good" as the kids say these days, I mean ill, not healthy, in need of treatment.

your valve clearance is bottom end. Take then all out to 08 and see.

As far as smoke, my money is on a gasket getting cooked. Any oil leaks around the engine? You have only had the bike a very short while, how new is the exhaust?

Michael