smoky 2 stroke

[maverick06]

I have a few 2 stroke engines, and i run them all at the same oil mix 40:1 (its the lowest common denominator, and I use cheap 2 stroke oil).

All of the engines work great. BUT one, a small 3hp (or so) snowblower, smokes a lot with it. Its all the same fuel and the other engines done smoke more than a normal 2 cycle. The snowblower was really beat up when I got it, and clearly had gas with huge ammounts of oil in it (not sure if it was 2 cycle oil or not). I have run it for a year or two since i got it. it still smokes a lot. (its a mtd 3/21 with the tecumseh hsk600 I think thats 3hp)

I guess the carb could be out of tune/gummed up.... or maybe the cylinder is really worn out. It still seems to be making tons of power (it never bogs down in snow). I cleaned the plug a year or two ago, I dont recall what it looked like then, the last year or two of service has left the plug looking nearly perfect. I dont have to use it too much, It plows my driveway well. I use it a few times a year and thats it. So i probably wont bother doing too much to it beyond shooting it up with carb cleaner, but was curious.

Thanks

 

[jharkin]

Maybe its tuned too rich? Pull the plug, is it all gummed up (rich), a nice golden brown, or white and ashy (lean)?

 

[MasterMech]

Most likely it doesn't like your oil. Try a different oil at the 50:1 or whatever the oil manufacturer recommends. There are oils that can be mixed 100:1 and provide the protection you're after without the smoke. They often wind up being just as economical as "cheap" 2-stroke oils. Opti-2 and AMSOIL Saber Professional are 2 that come to mind.

http://www.opti2-4.com/html/opti-2.html

http://www.amsoil.com/storefront/atp.aspx

 

[Joey]

Use some good Amsoil 2 stroke oil in your snowblower,,,see what happens. Also use some good quality fuel treatment, check out the Amsoil website,,,they make a few fuel system cleaners that may work for ya. I always had luck with their products. Also think its runnin a bit rich.....

 

[maverick06]

I pulled the plug, it looked pretty clean, no black buildup (after a year or so of light use)It did look golden and wet. I suspect that it is running slightly rich (gas rich, not oil rich). I have read that this specific engine doesnt have any carb adjustments, I find that hard to believe, The carb isnt easily accessible, so I havent found them, itf they are there.

I will definitely try a "better" oil once I am done burning what I have.

 

[StihlHead]

Never never never never never run cheap 2-stroke oil in an air cooled 2-cycle engine. Cringe!

Cheap 2-stroke oil smokes more, leaves more residue and deposits in the engine, gums up mufflers and spark plugs, does not have as good lubrication qualities, and it is likely not even rated for air cooled engines. 90% of 2-stroke oil is made for water cooled marine engines, and that stuff is rated TCW-3. That stuff will gum up an air cooled 2-stroke engine. You want an oil that is rated at least JASO FC or even better, FD. You also want to run 100% synthetic oil, as that will burn cleaner, your engines will run better, and they will last a LOT longer. In a pinch you can get away with JASO FB, which is what Castrol is rated at (or was when I last ran it). FB oil will smoke though. You can also run dyno oil, or dyno-synthetic mix, but that does not burn nearly as clean as 100% synthetic does. Read the can; if it is not rated, it is likely low quality or marine grade. Put it back on the shelf. If it says TCW anywhere, put it back on the shelf.

Go to any motorcycle shop and they will have good 2-stroke oil made for air cooled engines. Read the labels. The good ones are rated with JASO. I use Elf 100% synthetic myself. It is JASO FC/FD rated and it does not smoke at all. I run it in all my saws, blower and weedwhacker at 45:1 for a slightly better ring seal (Stihl recommends running 50:1). I would avoid running any oil rated at 100:1 unless you have some custom engines or the manufacturer recommends running it. Aimsoil is good, but it is expensive. So are a lot of other oils out there. Elf is (or was last I bought it) about $8 a liter, enough to make many gallons of premixed gas with. It is also tinted blue so you know if the gas has oil mixed in it.

I would also recommend that you use premium gas as well, and use gas stabilizer as soon as you buy the gas. Otherwise the gas will lose octane and the ethanol in there is likely to pick up water and separate from the gasoline (called phase separation, which will cause engine problems). Gas stabilizers like Sta-Bil will keep gas fresh for over a year, even in a small 2-stroke gas tank or a carberator bowl. No need to toss out the gas before storing for winter or after it has sat on the shelf for 6 month; just leave it in there with the stabilizer in it. Also, if you can, buy gas that does not have ethanol in it to run in your small engines. In some states that is impossible to do any more though.