smokin!!!!

[rodders32]

have a kx 250 2 stroke.....having just bought it second hand, never owned 2stroke before and when went out for first time is producing a fair bit of blue/white smoke..... power is good, no oil coming out of exhaust and doesnt seem to be losing any oil.

have i just mixed my fuel/oil wrong? what is the right amount of smoke?

only happens when accelorating.

cheeeerrrrssss:ride:

[asg5265]

Your rich on the jetting. Take the carb apart/ maybe off, and tell us what the Main and Pilot jets are and what altitude you run at. Also check the airscrews position. standard mix is between 36-32:1.

[TSmithCR250R]

2-strokes smoke. Not necessarily a bad thing... as asg5265 said, you may need to play with your jets or mix your fuel differently. Also, if you get that pipe hot enough the smoking should reduce... mine smokes like a beast when it's cold, but when it's up to temp... barely any smoke at all. I run 32:1 Klotz Super Techniplate

[asg5265]

I run klotz as well. You can run it lean and it will not seize. The hotter they get, the less smoke they make. They can also smoke real bad if they were lugged by the previous owner. my 200 had the same problem when I bought it, it was like a modded cummins motor that makes 700hp, smoke just everywhere.

[rodders32]

thanks....am gonna try and get my hands on a manual and will have a look at the carb. may just be the way i mixed the oil.

what did you mean 'lugged'?

[hi_im_sean]

they will smoke when cold, a properly running 2 stroke shouldnt smoke much at all, if at all when warm

[paolo h]

"lugged" means to run the engine at low rpm.

[TSmithCR250R]

yeah, you gotta keep er on that pipe and burn that sh%$ outta there!!

[hi_im_sean]

yeah, you gotta keep er on that pipe and burn that sh%$ outta there!!

no you dont, you just have to jet it for your conditions and style

[TSmithCR250R]

no you dont, you just have to jet it for your conditions and style

Yes yes yes...that was already clarified.....thheennnnn you ride it on the pipe!!! brrraaaappppp!! ?

[ridleyredraider]

Hold up though, you need to also make sure the top end isn't trashed out. If you just bought it, you don't know what's in there. Every two stroke I buy I drain the fluids, take the top end off, check the cylinder, piston, rings, powervalves, etc, then also inspect the clutch. You could mess with that carb constantly and never get decent power if the top end is trashed.

[asg5265]

Thats more important.

[rodders32]

The power is good, pulls strong and feels fine....just smokes quite a bit and still smokes when warm.

the other thing it does is engine dies unless keep throttle open partly, when stop wil die, doesnt do it all the time, so am leaning towards it needing carb setting up and idle speed raising....i think???

[asg5265]

Its easy to turn up the idle. Your def rich and fat on the jetting...

[hi_im_sean]

Its easy to turn up the idle. Your def rich and fat on the jetting...

i would agree, lean out that pilot

[rodders32]

uuummmmm.....kinda feeling bit on the dumb side now!!!! never had 2 stroke before and so never done the oil mixin bit....just done the maths on how I mixed it and I would have had a mix of something around 20-1!!!

am kinda thinkin this is why she may have been smokin a little???? wow I am dumb!!

i will still sort the idling problem and thanks to an amazing member on here i now have the pdf manual for my bike for free....you are a top gent!!!!

[The Spanky]

2-strokes smoke.

A properly jetted two-stroke does NOT smoke when up to full operating temperature. With correct jetting you'll achieve combustion temperatures in the 4000-6000F range, more than sufficient to completely consume the oil. With proper jetting you can run 18:1 if you wish and have no smoke or spooge.

Assuming the wet-side crank seal is not leaking, I concur with the rich jetting diagnosis.

[TSmithCR250R]

A properly jetted two-stroke does NOT smoke when up to full operating temperature. With correct jetting you'll achieve combustion temperatures in the 4000-6000F range, more than sufficient to completely consume the oil. With proper jetting you can run 18:1 if you wish and have no smoke or spooge.

Assuming the wet-side crank seal is not leaking, I concur with the rich jetting diagnosis.

If you read and quoted past my post "2 strokes smoke" you would see that I say the same thing... ?

[rodders32]

have reset the air screw....the idle adjust screw doesnt seem to make much difference to engine note??

took plug out is black as ace of spades....is def running way to rich, do i have to strip the carb down and replace jet or is it just and adjustment??

[asg5265]

well you can usually change jets on a 2t just by loosening carb clamps, unscrewing the top cap, pull out top, then rotate bottom of carb out to you then take off bowl. Watch out tho, stuff can come apart on disassembly, just look at the thing and figure it out, its not to hard. It also helps to take the carb below the 90 angle to keep stuff together. Also dont forget to drain fuel out of the bowl first by removing the plug, clean out bottom of plug too. dont tighten bowl screws to much, you are going into aluminum, use common sense.