White smoke always coolant or motor oil???

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#1
I've been working on the jetting of my bike and I have all the indications of running rich - dark oily plug and oil drops from the silencer. When at idle and especially coming off idle I get huge clouds of smoke.

However, the smoke color is white not bluish. I've tried running yamalube and currently motul at 40:1. My coolant level stays completely constant and I am sure there is no coolant getting into the cylinder.

My motor oil (80w) level seems to be fine, I have never had it drop below the sight window. Although, given how imprecise using the sight window is I am not 100% sure that a little motor oil isn't getting past a seal somewhere.

What I'm wondering is if it is possible that the white smoke is just 2stroke oil and gas???? I hope so because I really don't want to have to split the cases. If it helps the bike is a 90kdx200 with 150 main, 42 pilot, cel in midclip. Mods include pc pipe and silencer, airbox lid removed, and boyesen reeds.

Thanks
 

Houndog

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#2
From my experience (for what that's worth...)

White smoke is coolant
Blue smoke is oil (or jetted too rich in a 2 stroke)
Black smoke is gas (rich, at least in a 4 stroke)
 
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#3
I would say my smoke is grayish white. Are there any inexpensive ways to figure out what is causing it? I asked my local shop about a vacuum test and I think I saw dollar signs in their eyes.

When I mentioned that I was concerned about the crank seals they didn't realize on my bike they couldn't be replaced without splitting the case.

I love this bike, but it's hard for me to keep throwing money at it. If anybody has any ideas I'm all ears.
 
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CaptainObvious

Formally known as RV6Junkie
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#6
Does the smoke smell sweet? Coolant has a sweet smell to it. Oil smells like...oil.
 
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#7
No sweet smell, doesn't have much odor at all. If I had to choose one though I would say it smells more like oil.

Yesterday when playing with it I noticed it making a 'crackling' sound at lower rpms (about up to 1/2 throttle) which I gather is a sign of running rich.

I've got more pilot jets coming in the mail - 35,38, and 40. It seems like I'm running a lot leaner jets than anybody else with my model bike though. I'm guessing that I may end up with the 38 to get rid of the crackling.

Is burning motor oil a distinctly different color than burning premix oil usually?

I am wondering if oil is getting past a crank seal & getting somewhat combusted (giving the whitish smoke) and making my jetting very lean to compensate.
 

tedkxkdx

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#8
If your crank seals are blown you will loose lots of oil from the tranny. At first I did not notice the smoke then I noticed my oil level dropping and then 2 + 2 = lots of money to fix on its own so I sent it to fredette for any thing he wanted to do. It was way cheaper to have him do it along with porting and going to a 211cc than just taking it to a dealer. Or buy your own case splitting tools and have someone help you do it.
 
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#10
I'm in Tallahassee, FL - just moved up here from Gainesville, FL. It's high temp, high humidity, and low altitude (probably 20ft above sea level).

I know these conditions should make the bike run richer, but even so it seems like I'm jetted alot leaner than any other posts I remember reading (for this carb & setup).

Hopefully, I can get out and do some riding this weekend. Maybe make my first trip to Apalachicola national forest.
 
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#12
I just wanted to post the results of my jetting experience from the past couple weeks in case anyone is interested.

After finally getting the carb to stop peeing - thanks again Wibby for the tip about using wet and dry on a cuetip to polish up the float valve needle seat - I was able to get to work on the jetting. I ended up dropping 2 sizes in the main and 3 sizes in the pilot. I'm now running a 152 main, 38 pilot, and CEL in 2nd clip.

The kdx was running like a champ. I had no idea that it had that kind of power inside it waiting to get out. I took out my 93 cr250 with it and for the most part the kdx was pulling as hard if not harder than the cr.

What's scary is that I still think there is still a little room for improvement on the jetting. There was a little black spooge coming out of the silencer after Sunday's ride.

Thanks again to everyone who helped me out. Hope to see you on the trails someday.