2 stroke tuning. excess smoke?

[McBiggity]

Wirelessly posted (BlackBerry8330/4.5.0.77 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/105)

How would one go about tuning a 2 stroke to reduce the amount of smoke being produced?

[Sheppo]

Full Synthetic oil mixed 50:1 Mine isn't too bad smokewise.

[gregp]

Tuning (carb jetting) to reduce smoke is not the best idea. 2 strokes burn oil by design, and you may lean your mixture out too far in attempts to reduce smoke. A better approach is to try some of the newer synthetic "smokeless" oils on the market today.
Golden Spectro, Amsoil, and others claim reduced visible smoke.
I like to run castor products (Klotz, BeNol, Castor 927, etc.) simply because I like the smell.

[Paul_E_D]

Excess smoke is usually a rich condition. Is there drool coming out of the tailpipe? Is the plug black?

It's not always the main jet that's rich as we usually are on and off the gas a lot on dirt, indicating that the needle and pilot may be overly rich.

Try dropping the needle 2 clip positions (raise the clip) and see if the smoke clears any. Trouble is your muffler packing is likely spooged up, meaning it's gonna smoke til that gets burnt out.

Oil choice can generate smoke too. A good synthetic smokeless is in order.

My bike smokes very little except at cold startup.

Get a range of about 4 mains and 3 pilots (probably go leaner than what's in there) Also get a leaner needle (bigger number) Then do some testing.

[Paul_E_D]

Tuning (carb jetting) to reduce smoke is not the best idea. 2 strokes burn oil by design, and you may lean your mixture out too far in attempts to reduce smoke. A better approach is to try some of the newer synthetic "smokeless" oils on the market today.
Golden Spectro, Amsoil, and others claim reduced visible smoke.
I like to run castor products (Klotz, BeNol, Castor 927, etc.) simply because I like the smell.

Ha! I just suggested jetting! In my experience though, a properly jetted bike smokes a lot less.

[McBiggity]

I'll start with a better oil and go from there.
The manual says 32:1 and that's what ratio I have been using. I could try a different ratio as well.

[Sheppo]

better oils are more concentrated so a 44:1 or 50:1 isn't unheard of. I am using Amsoil full Synth 'smokeless'

[seth399]

ya what paul and these dudes said. Mine smokes when I start it up cold pretty good, then goes away. I use Amsoil Dominator at 50:1

[Kitt]

I like to run castor products (Klotz, BeNol, Castor 927, etc.) simply because I like the smell.

miss my 2-smoke smell!

[typeone]

I use Amsoil Dominator at 50:1

for the Dominator at 50:1, my CR250 smoked very little using it. jetting was pretty spot-on though too.. .

[seth399]

miss my 2-smoke smell!

premix and VP...yummm

[Kitt]

premix and VP...yummm

VP burns eyes... premix+VP hurts so good

[Sheppo]

I use Cam2 I can get it at the pump in Hudson NH

[gregp]

Ha! I just suggested jetting! In my experience though, a properly jetted bike smokes a lot less.

LOL! I guess that I should re-phrase what I said. Most *stock* 2 strokes will be jetted richly, and could probably stand to be leaned out a bit, both at the top and bottom. However, I would recommend staying with the bike manufacturers recommended oil mixture (32:1, 40:1, whatever) *or* the oil manufacturers recomended mixture - your pick - and then leaning your bike out a bit (if you are sure that somebody hasn't already done this to your bike). Do not lean out the oil mixture!
You can do plug chops, and jet by the seat of you pants - tending to rich "zones" in your jetting, but be careful not to lean your jetting out so far as to cause engine damage in pursuit of a smokeless exhaust!
Simply switching to a smokeless oil would be a more prudent approach if a clean exhaust is what you are after.
Personally, I never understood why folks pursue this. A spoogy smelly exhaust is all part of the classic two stroke experience, especially if you run castor products.
There. I feel better now.

[Paul_E_D]

Nah, a spoogy, smelly exhaust will undoubtedly accompany a bike that is nowhere near crisp. The best part of 2 strokes IMO is how responsive they are to tuning. no fuel injection I've sampled compares to a dialed in 2 stroke. Most people ride bikes that bog, sputter, or fall flat somewhere in the rev range.