new to two strokes and dirt - excessive smoke

[red66chevelle]

i have been riding and working on bikes for about six years, and i recently purchaced my first dirtbike... a 1990 kx250.  the bike was leaking coolant into the tranny, but i think i fixed the problem by replacing the water pump oit seal. (ill know the next time i go out for a day) anyway...  the bike seems to bogg at lower rpm in first geat in particular (which may be normal for a kx250 or any 2 stroke bike - but im new) and smokes and drips lots out the silencer. other than that the bike seems to run great. starts right up and had plenty of power once up in the rpm.   i was running a buddies premix of 20:1 for a few days not knowing any better and finally got the service manual and then ran the suggested 32:1.  is the excessive smoking normal and if not what may be causing it... jetting, mixture, fiberglass in the silencer?

thanks for any help and sorry about being so new.
[i dont believe it took me this ling to get in the dirt!!!]

[hoopty]

Modern synthetics are wonderful things, I run my 500 @ 100:1 with Amsoil Pro 100. No smoke, no spooge. Been running that way for years and never had a problem.

Oh, welcome to the site  

[GSTinCO]

^^^^ Synthetics are great, they will be your best friend. Enjoy the dirt.

[Timbowe]

250s are a bit low in the power dept at the lower end of the band. Try a reed block spacer and/or Veeforce reed block to broaden the power curve. Makes things a lot more user friendly.
 Amsoil user here from way back! Imagine your poor engine try to run decently with a fifth of the fuel mix dirty thick s**tty oil!!! Synthetics have the protection and run very clean. Try it. you wont be dissapointed!

[01KX5WOODSRIDER]

I used to have a 91kx250. I now have a 96kx250. They both pull good from right above
idle. I would do a compression check on the top end and watch the tranny oil level to see
if maybe crank seals are letting oil into top end. I ran 32-1 oil in gas and didn't have excess smoking. If you trail ride your 250 it may help to lower needle a notch and also go a size or two lower on idle jet.

[gowen]

Hey nice TL1k! If it is smoking it is from your jetting being off, reguardless of your mixture, it won't smoke much. If you have  your jetting set accordingly you should see little to NO smoke. Start at the main jet and make your way back. If you have a rich mainjet and try to adjust the pilot jet, it will not help much. I usally try to find the most crisp throttle responce. Great source for a start is FMF's webpage for a start, make sure you are on par. If you need more help on this, we have a few experts in this area.

[hughes]

I agree with Gowen. But I would check my float height before you try and start to jet the engine/carb. I use Yamalube 2-R mixed at 32:1 in my 500 and do not have any oily stuff leaking out of the pipes. A 90 model bike I am sure the float height is going to be off from wear and tear. Let us know what you come up with.

[gowen]

I agree with Gowen. But I would check my float height before you try and start to jet the engine/carb. I use Yamalube 2-R mixed at 32:1 in my 500 and do not have any oily stuff leaking out of the pipes. A 90 model bike I am sure the float height is going to be off from wear and tear. Let us know what you come up with.

  oh yeah, check the float height first. Thanks hughes.  

[KXcam22]

Nice bike collection!  What is the red one I can't quite tell.  I'm another synthetic oil faithfull.  Ater 35 years, my particular oil of choice for the last 20 is Belray MC-1 at 60:1.  There are lots of great synthetic brands but the Belray has always been my choice.  Others may run variuos mixes but I never run any engine I own richer than 50:1, and thats even in my weed whacker and chainsaw.  Heck my yamaha outboard runs 100:1.  Given that the bike is a 1990 I would suggest a compression check. That could explain the smoke and the poor bottom end power.  Welcome to the site. cam.