I have stihl chain saw it runes full throttle

centrifugal clutch problem
replace it

adjust it at the throttle end on the carby
if you have the correct tool you can adjust the idle mixture as well

There are several conditions and situations that this can occur, but let's try the most common. This is also for any STIHL saw that was manufactured before 2014, after that, the M-Tronic saws have a different starting method.
Normally this happens when the engine fired and it was not audible, and the rope has continued to be pulled with the choke on.
This method is approved, but EXTREME caution should be used, and the CHAIN BRAKE must be used.
CAUTION: Do NOT use the drop start method, this is not an approved starting method under any circumstance!
1) Place the saw on the ground that is clear of debris.
2) Set the Chain Brake
b) place the toe of your right shoe thru the rear handle,
c) support the saw top handle with your left hand,
d) pull the recoil with your right hand.
3) Make sure the choke is NOT applied, place the master control lever in the start position (one notch above the choke position)
NOTE: at this point, it helps if a second person can hold the throttle at the full or wide open position.
4) Make 6 rapid pulls (a few more may be required), you should hear the saw start to sputter, keep the throttle open until enough rpm is obtained that YOU the Operator can gain control of the throttle (the other person stands aside now in a safe position) and remove the chain brake. Keep the throttle open until the saw starts to run properly.
*NOTE 2: The chain brake is designed to not only stop the chain in case of 'kick back', but also is to be used in starting the saw until you have time to gain full operational control of the saw. However, extended rpms above clutch engagement can damage the brake band, overheat the drum bearing, damage the clutch shoes and clutch drum.

I’m happy to assist further over the phone at https://www.6ya.com/expert/rolandw_c013176d62ee17ae

carby idle adjustment or a carby kit and clean needed

carby has a high and a low rpm jets

STIHL MS 290, 310, 390

https://www.stihlusa.com/.../instructionmanuals/stihl-ms-290-310-390-owners-instructio...
Instruction Manual - improper use can cause serious or fatal injury. MS 290. Warning! ..... model. Safe use of a chainsaw involves. 1. the operator. 2. the saw.

Is the saw oiling correctly? need to check the RPM's at full throttle with bar and chain on to see if it is running right with a tachometer. I suggest taking it to a dealer to have them do the STIHL Engine Check List to determine the exact cause

If you need further help, I’m available over the phone at https://www.6ya.com/expert/kelly_69a0cf1b13789df1

The "L" is your idle setting and the "H" is the wide open fuel setting. After the engine starts and runs a minute adjust the "L" to the smoothest run setting the go full throttle and adjust the "H" the same way.

Hope this helps.

Generally this is a fuel / air ratio problem. Usually it can be solved by a carb adjustment. On the carb there are usually two screws, one marked low or L , the other marked high or H. Low is your adjustment for idle mixture, high is for mixture at full throttle. The saw should Always be adjusted to run well during the cut. Make adjustments a little at a time, then try The saw. Continue small adjustments untill the saw is performing well at full throttle while Cutting.

I would say it is flooding, you realy need to pressure test the carb to check the seating of the inlet needle, a simple bulb tester is all you need, connect it to the fuel inlet on the carb ( where the fuel hose is connected ), pump approx 2/3 psi into the carb, it should hold this steady with no leak, any leaks then you will have to fit a new inlet needle, let us know how the test goes.

Yes! So here are some links:


STIHL Ematic™ guide bars are engineered and manufactured to STIHL's strict quality control standards and are produced in STlHL's own factories. STIHL offers a full line of guide bars for all types of use from 10" for specialized wood carving applications with small saws through 59" for extreme felling operations. Explore our products to find the STIHL guide bar that's right for you. Locate your local STIHL dealer.


STIHL ROLLOMATIC® ES Super STIHL ROLLOMATIC® E Light
STIHL ROLLOMATIC® E Standard STIHL ROLLOMATIC® Mini
STIHL DUROMATIC® E Carving Guide Bar
Thumbs back!

I'm not sure there are any "endorsed" tuning specs from Stihl as weather, temperature, fuel quality etc all contribute to engine performance.
Pictures of all types are all over the web.

As for the carb tuning procedure, maybe I can help?

Start with fresh fuel, all filters clean, and bar and chain installed. Also, fill the chain oil tank with bar/chain oil and VERIFY that the chain oiler works properly.
Initial fuel mixture settings (the H and L screws) should be 1.5 - 2 complete revolutions counter clockwise from lightly seated. Sight the carb's throttle plate and adjust idle screw counter clockwise until the plate stops moving.(Throttle closed completely.) Then go back clockwise 3 complete revolutions. This will produce an acceptable startup condition on a HEALTHY saw.
Clamp the bar in a STURDY bench vise and roll the chain with the shank of a screwdriver to verify it is clear. BE SAFE!
Choke the saw and pull the starter rope until the engine "burps".
NOTE: If no burp after 6 pulls, stop! Something is wrong.
After the burp, set choke to half and pull starter until it runs. The settings I gave should produce a slightly rich condition and a slightly high idle. (Chain will be in motion!)

Blip the throttle trigger and idle it down just enough to keep it running during the tune procedure.
Step 1) Using the "L" screw (closest to the engine), turn it clockwise until the engine smooths out or possibly increases RPM. Back it out slightly until the engine has a slight "LOPE" sound to it. (Like a drag car on nitro).
Step 2) Accelerate the engine to full throttle and go to the "H" screw (closest to the air filter) and slowly turn it clockwise and note the RPM increase. There will come a point when the saw will "Top-Out" and loose power. Not even enough power to turn an maintain empty chain's RPM! Go back counter clockwise to the edge of that point, and counter clockwise another fourth (1/4) revolution.
Step 3) Idle the saw back down. Again go to the "L" screw and repeat Step 1.
Step 4) Repeat Step 2.
Step 5) Idle the saw down until the chain stops moving completely. NOTE: Don't settle for a "crawling chain" condition. If the steps above are performed well and all else is healthy, you should be able to idle the engine down to a ridiculously low RPM and it will not shut off.

Hope this helps,
Dolf-