Chainsaw adjustment

[Rat Rod Mac]

I have a Stihl 024 chainsaw I bought new 20 years ago and it still runs fine until recently. Ran good last fall when I put it away. Got it out yesterday and it would not idle at all and even when it was revved up would surge ( rev up then down then up slighty ). Thought it might be the gas since it sat all winter. Bought a gallon of 89 octane with a small bottle of oil and a new plug and air filter. Ran a little better, but now I think I need to go back to the original carburator settings and start over with the carb. adjustments. Does anyone here know how to adjust these carbs? High speed jet, Low speed jet and idle. Thanks. RRM

 

[smstonypoint]

The Stihl web site has online manuals for a lot of saws, but not the 024. The manuals for other saws may help. The site includes a link allowing you to order printed manuals.

STIHL Incorporated USA -- Information -- Manufacturing the World's Number One Selling Brand of Chain Saws

 

[amaxwell]

You might also check to make sure the plastic fuel lines have no cracks: or that it is not getting extra air from a bad gasket.

Alton

 

[Gator6x4]

I have a Stihl 024 chainsaw I bought new 20 years ago and it still runs fine until recently. Ran good last fall when I put it away. Got it out yesterday and it would not idle at all and even when it was revved up would surge ( rev up then down then up slighty ). Thought it might be the gas since it sat all winter. Bought a gallon of 89 octane with a small bottle of oil and a new plug and air filter. Ran a little better, but now I think I need to go back to the original carburator settings and start over with the carb. adjustments. Does anyone here know how to adjust these carbs? High speed jet, Low speed jet and idle. Thanks. RRM

I will try. Adjust the idle screw in until the engine will run at idle. Now turn the low speed adjusting screw in until the engine RPM's start to drop. Now back the screw out until the engine runs smoothly. Now hold the throttle wide open and turn the high speed adjusting screw in until engine RPM's start to decrease, now back the adjusting screw out until the engine obtains maximum RPM's. By listening to the engine you can hear the "Sweet" spot as you are backing the adjusting screw out. You will probably have to readjust the idle and low speed high speed a couple of times to get it right.

 

[MikeD74T]

What Gator said and empty the tank & run it dry when you're not going to use it for a while. Gasohol is reap crap in small engines. MikeD74T

 

[Treemonkey1000]

I would check your tank filter. For a few bucks just replace it actually on a saw of that vintage. As someone else said your fuel lines can crack or they get so soft and kink or collapse stopping the fuel.
Next thing if you try some of the mentioned adjustments and it is still not running right then take the carb off. Drop the diaphragm screw on the bottom of the carb. You will find a little mylar or rubber diaphragm in there. Carefully take it out noting which side was down and which direction it came out. More than likely some crud is in there. Wipe it out with a clean cloth. If you try to spray it out with carb cleaner keep your face away from it. That stuff is NO fun in the eyes.
Usually the fun part is getting the linkage to the throttle hooked up as well as the fuel line.
You mentioned using the high octane gas. I always use the high octane in my saws, wood splitter and chipper and even my Hemi dodge. These little engines run better on the good stuff I think.

 

[sms0000]

Probably needs a good freshen-up, clean carb/jets, check/replace piston & rings and all new gaskets/lines, new fuel filter in tank. Should cost a helluva lot less than buying a new one....that is if your handy and can DIY. It'll be good for another 20 or so .

 

[arrow]

Surging is a differential mismanagement of fuel/air mix that can include exhaust flow. lets start with the simplest stuff first. Also. right now, do not attempt to change any needle screw settings unless someone borrowed the saw and may have messed with them. 1. Change gas. 2. If that's been done, blow out or replace air filter or see if saw runs fine w/o filter. (Do not use saw w/o filter as this is just a diagnostic test) 3. Remove muffler and clean out spark arrester plate. (largest symtom of this is saw would run for a short while and then shut down and restart and run fine after cooling and then repeat a shut down) After that is attempted then I'd check things like fuel filters and integrity of gas lines and spark strength. I doubt you have an air leak at carb base. As far as settings, most saw use the highspeed setting for upper rpm management but this setting is also used for acceleration smoothness. If saw bogs at triiger press, that is considered a highspeed setting arena even though problem starts at low rpm's where you would think it may be low speed. Also, for the sake of longevity, do not run saw at highest rpm setting. Back it down until you hear the engine starting to 4 stroke. ( you'll know the sound). If it were me, I wouldn't be so quick to mess with the screws right now until other stuff is looked at as described above. You have seemed to take care of most already with exception of cleaning out muffler and spark strength. Also, be sure to use recommended octane settings form manufacturer. There has been much discussion about chainsaws and octane and consensous is all over the map. When it doubt, use the MR.

 

[pat32rf]

I keep having mechanics tell me that the regular gas may contain alcohol/methanol, but the hi-test never does. The alcohol is murder on some of the plastic/rubber carb parts.
I'd check the spark arresting filter before messing with the carb, just went thru the same problems with my 026.
Finally took it to the dealer, who explained that after 20yrs of use, the compression might be starting to go and I should expect future problems

 

[RobertN]

024's are GREAT saws. I have my Dad's here, and am rebuilding an 024 Super.

I have found, especially after sitting, the gas line will turn to mush. On my Dad's saw, it simply fell apart. The saw will not get enough gas.

The fuel filter can get gummed up. This is an older, 80's saw. I would replace both the fuel line and the fuel filter.

Saws, not just this one, will run odd if the impulse line gets old or cracked. The impulse line goes from the carb to the crankcase; it is what works with the carb to "pump" the gas.

There should be a screen on the muffler. If that spark arrester screen gets dirty, the saw can not breath; it "clogs up" the muffler.

The other thing is, the crank seals tend to go on these saws as they age...

And, of course, the carb can gunk up.

I would:
- replace the fuel line and filter.
- check the impulse line(have to remove top cover, snakes by the carb down to the crankcase
- clean the muffler screen
- reset the mixture screw to factory setting

Try to run it then. If you adjust the mixture screws, they should only need minor adjustment.

If that does not help, try a carb rebuild.

Otherwise, it will need a compression, pressure, and vacuum test done to check the rings and the crank seals.

Stihl carries parts for that saw. So does Bailey's. Service manuals are available on the web for $15-20.

These are great saws. Expensive to replace; the current equivilant would be a $500 MS260.

Oh, and aboristsite is like the TBN of chainsaws; an amazing wealth of knowledge. A search for "024" over ther will give you all kinds of info on that saw, and how to repair it.
- put fresh gas in; premium gas and premium Stihl oil