How to set carb on stihl chainsaw
Chris Deziel has a bachelor's degree in physics and a master's degree in humanities. Back off at least one-quarter turn immediately.
Chris Deziel has a bachelor's degree in physics and a master's degree in humanities. Besides having an abiding interest in popular science, Deziel has been active in the building and home design trades since As a landscape builder, he helped establish two gardening companies. Skip to main content. Home Guides Home Home Improvement. Home Guides Home Home Improvement Smoking or faltering usually means your saw's carburetor needs adjusting.
Tips Never adjust the carburetor when the air filter is dirty. These changes include working at different elevations, changes in fuel, and a host of other factors cause saws to need periodic carburetor adjustment. With this technology, saws will be able to "self adjust.
The process of miniaturizing an economical and durable system that will work on a saw engine is being developed.
Until then, keep your tachometer and screwdriver handy. The preceding information briefly explains rich and lean running conditions. It also identifies the three adjustment screws and their function. It should be noted that on today's pro saws, most of these adjustments have "limiters" that limit the range of carburetor adjustment.
In most cases, proper adjustment is within this range, but not always. If proper adjustment for your saw is outside the limited range, take your saw into a shop. Sometimes this is caused by a problem with your saw, and sometimes the range on the limiters just needs to be reset. If this adjustment is set too low, the engine will die when the throttle trigger is released.
If this adjustment is set too high, the high idle speed will cause the centrifugal clutch to engage and the chain will run. This is a dangerous condition. An adjustment that is too rich will cause the engine to load up and die at idle speed. A mixture that is too lean will starve the engine and cause it to race or surge. An extremely lean adjustment will cause the engine to die, too.
How to Adjust the Carburetor on Stihl Chainsaws
It would not be accurate to say this is the most important setting, because all of these adjustments need to be accurate for a saw to perform its best, but this is the adjustment that determines how the saw runs in the cut.
An adjustment that is set too rich will not allow the saw to reach the RPM level necessary to build maximum power. Throttle response may also be sluggish and the engine will smoke and perform poorly. A mixture that is too lean will allow the engine to reach an RPM level where bearing failure and cylinder seizure are likely.
It will also lack power in the cut and tend to run very hot. Keeping the carburetor adjusted properly will ensure optimal performance for your Stihl chainsaw. Remove the air filter cover, just above the throttle, by unscrewing the black knob. Take off the cover and unscrew the air filter. Clean them both with a wire brush and a little gasoline. Replace the air filter if it's too dirty to clean or damaged and put the air filter back on the saw. Use the Allen wrench to remove the muffler cover.
Pull out and clean the spark arresting screen with the metal brush. Start the saw and let it idle for a few minutes to warm up.
Locate the three small carburetor screws just above the clutch cover. Some models may have a protective plastic plug covering these screws. Pop those off with the screwdriver to access the screws. Adjust the idle speed, or the bottom screw marked with LA, clockwise until the chain starts moving on its own. Have you determined whether or not you have spark?
That would be the first step. Pull the plug out, connect it to the plug wire, and let it touch a metal part of the saw. Then pull the cord while watching the electrode on the plug. If it sparks, chances are that the ignition is ok and we can go further. If not, you have ignition problems.
Sounds like an air leak.
How to Adjust the Air and Fuel on a Stihl Chainsaw
If you can run an engine on full choke, you definitely have an air leak somewhere, you would have to have the mixture screw bottomed out to run that lean. If those are good check the cylinder bolts are tight too. An old trick to find a vacuum leak is to get it running and spray choke or carb cleaner around it—when the revs go up listen for a change in exhaust note. If no air how are found the carburetor may have a problem and need to be rebuilt. Derek, I just had the same issue.
I rebuilt the walbro carb on my stihlnew gaskets, replaced the screen you were talking about. I also used a can of carb and choke cleaner and sprayed it thru all the holes. Even removed the high and low needle set and sprayed thru them. I re-assembled the carb great video on you-tube.
But I also replaced the fuel line and filter. It started on the second pull woooohoooo. Make sure you get the correct fuel line. If yours is an older stihl you may need the straight fuel line, not the one with the pre-bend in it. Also check your fuel tank vent. If it is clogged it wont let the carb pull gas. Also when looking at your carb from the handle make sure the impulse line right side bottom is fully attached to the carb. Now reassemble and seat the L and H screws Clockwise to stop. Now choke and start. Again search youtube for stihl carb rebuild video. I been in small tools for Mostly partner and large construction equipment as well as small tools.
Here the problem, have a Stihl TS on the bench came in not running. Actually looks like someone found it at the bottom of a lake. Anyway, torn it down cleaned it up. Low compression, so replaced piston and jug and rings. Replaced carburetor with new one. Clean gas tank and replaced filter and fuel lines. Problem is I can not get any fuel to pump to the carburetor. Did a pressure test on fuel line and tank no leaks.
Set a leak down test on Piston and jug. Also did a pressure test on new carb just to make sure no leaks. So I figure I should have had a leak some how. Still scratching my head. Can any one give me something else to look for or do.
Oh yes replace plug and yes I fired it up with direct gas to carb and it ran on that fuel only and shut off. Sounds like you have all the bases covered but here goes. Change the fuel line and filter if the fuel line has a pin hole in it, the engine will suck nothing but air.