[LOUIECCC]

Old 2-cycle oil has two basic problems. The first is that the oil itself becomes unstable in the presence of solvents like gasoline, thinning it and converting its inherent viscosity into a sticky film that clogs filters and carburetors. This varnish is similar to that found in any gasoline engine, but the disassembled oil molecules make it thicker and stickier. The second problem is that most modern gasoline contains ethanol, which can eat fuel lines and hasten the breakdown of oil. Along with the usual fuel varnish, dissolved rubber works its way though the system's filters and into the carburetor's small passages. [links]

[jelon94]

The fact that you add oil to the fuel in 2-cycle engines changes many of the fuel's characteristics, including the ways in which it rots and the cleaning procedures required to remove it. Whereas most techniques used to refresh a 2-cycle's fuel system are almost identical to those used for conventional 4-stroke applications, care needs to be taken to rid the system of spoiled oil as well as fuel.

[jgarzik]

If your engine has already been run with bad fuel but still works, you might be able to get away with a 2-cycle-specific marine fuel conditioner like those sold by Evinrude. For an average of about $6 a bottle, as of 2010, such fuel conditioners do a great job of dissolving built-up varnish and gum in the fuel system. You could use a standard automotive additive, but many of these do such a good job of dissolving oil that they break down the molecules required to keep the engine slick and happy. Marine additives are used like any other; simply add them to the tank (8 oz. of additive for every 32 gallons or less of fuel) and run the engine at part throttle until the tank runs dry. If the engine still runs badly, then you'll need to go a little more in-depth with your cleaning. more

[Drunken F00l]

If the rubber molecules floating around in your fuel system have irrevocably clogged the fuel filters, replacement is necessary. After you replace the in-tank fuel filter, the inline filter and the carburetor filter, you should seriously consider replacing your stock rubber lines with those specifically designed for use with ethanol. Otherwise, you're looking at perhaps two years between line replacements. [links]

[wolfz0rz]

All you really need to do is buy an ultrasonic cleaning solution and place the part inside the device, turn it on and let it do it’s thing. You’ll notice a high ringing sound so you’ll maybe need to put it in a room you don’t plan on staying in if that type of sound annoys you. I like this specific ultrasonic cleaner because it has a heater that heats up the solution for that extra thorough clean.

[Koon]

I have created a video series about restoring motorcycles from start to finish and within this series includes a detailed 25 minute video on how to clean and rebuild carburetors. This series also includes other hard-to-tackle components such as body work and electrical. I give dozens of tips and tricks that you won’t find anywhere else online. Click here for more information if you’re interested in viewing multiple videos that will help fix up your bike or if you’re interested in completely building your dream motorcycle!

[MrBison]

When it comes to carburetor issues, it can be a nuisance trying to take it off the motorcycle, taking it apart, and figuring out what exactly is causing the problem. Though they’re a simple mechanism, they have tiny parts that’s could easily be lost when taken apart.

[cyclonite]

These are easily clogged especially when ethanol gas is used. Clogged jets are the number one reason a carburetor doesn’t work right. To learn more about the right type of gas to use on your motorcycle, see my article here. more

[SmokeTooMuch]

However, sometimes a quick clean like this doesn’t always work. There may be some other underlying issues within the carburetor that you may need to look at. This, unfortunately, means you’ll need to take the carburetor off the motorcycle.

[Xobbit]

I have cleaned over a hundred carburetors over the last few years and I have cleaned them in every way imaginable. I’ve had success cleaning some without having to remove it and this is how I did it.

[kldunc]

When cleaning a carburetor of a chainsaw that doesn't start, check the air filter. If the filter is dirty or clogged, it will be apparent when you examine it. A clogged or dirty filter will prevent needed air from being drawn into the carburetor's combustion chamber. A dirty or clogged filter, if it's metal, can sometimes be cleaned by swishing it in a liquid cleaning agent. If the filter is made of paper or other material likely to disintegrate in liquids, you will probably need to replace it.

[gohan]

Give your pull cord several strong pulls, alternating with several pauses to allow the additive to dissolve gummy deposits. Sometimes this cleaning requires a flow of fuel with the cleaning agent in it over these gummed up surfaces. Even though the saw may not be running yet, just pulling the cord, when combined with a few rest intervals, can move the cleaning agent through the carburetor valves enough to clean off any residue left on their surfaces. [links]

[plusjeans]

You will be able to clean a chainsaw carburetor more efficiently if you understand that its two basic functions are to deliver air and fuel to a combustion chamber in the engine. This should help you understand that in cleaning the carburetor, you may need to clean the channels for both air and fuel. This can be done in 5 simple steps.

[SergGT]

At times the problem may be caused by old fuel or fuel into which moisture has condensed and contaminated the old fuel. If this is the case, empty the old gasoline from the tank and refill it with fresh gas.

[tddk]

Don't think that would be a good idea for my saw, but who knows? here

[harrison801]

That is what I am doing my self too! I am adding 1 oz plus 1 oz of stabil per gallon. It is a wee bit stinky but my 2 stroke *** carbs and combustion chambers are nice and clean. For my wood splitter and riding lawn mower. I am using 1 oz marvel mystery oil plus 1/2 oz of stabil per gallon. more

[drwhite]

Back in the day with my checy truck with a 4 bbl, we would always rap the the throttle and pour ATF down the throat. worked really well. more

[canvasprint]

a trick way to do this is with carb cleaner with a nozzle. but make sure piston is lubed after you do this. carb cleaner is specifically designed to remove gasoline related gunk. works much faster than seafoam.