High and Low Carburetor Adjustment on a Stihl Trimmer

The carburetors on trimmers, blowers, weedeaters, and other small engine equipment, have several adjustments screws. If your equiment won't stay running or isn't running correctly, you may be able to adjust these screws to get it to run better. The high adjustment screw should be adjusted at full throttle. The low adjustment screw should be adjusted at idle. The idle adjustment screw should be adjusted at idle and is basically just adding or releasing tension to the throttle cable. If your equipment dies when you release the trigger, try adjusting the idle adjustment screw first, so that it adds tension to the throttle cable. If this adjustment doesn't work, it's possible you need to adjust the low adjustment screw. If your equipment lacks power and the rpm's sound too low or if it sounds like the rpm's are revving too high, you may need to adjust the high screw. This video shows how to make those adjustments on a Stihl FS-90 trimmer.

[davidcolston]

Glad to see some one explaining how to adjust the carburetor without confusion. Thanks!

[eddybarroso]

saved me about a hundred dollar on a simple tool and video straight to the point thanks man ! very good

[joeogle]

Thanks for taking the time to explain in detail. You would be surprised how many dummies there are trying to teach!

[mimik]

Great video! All my questions were answered. I'm sad he isn't active anymore...😢 Come back and teach us more!

[WVChad]

I adjusted my fs 90 with no problems after watching this video. Thank you. I noticed I had a missing nut holding on my carb which I replaced and that was probably half my problem with it not running right. I was able to set the high speed adjustment so it spins like it should at full throttle and I was able to adjust the idle so the head doesn’t turn anymore when it is idling. I was just about ready to buy a new weedeater. Thank you

[locqtusofborg]

VERY HELPFUL: simple, to the point, covered all adjustment points. Thank you

[laven]

You helped me a lot on this . I have a 133 and it would start and die . I adjusted the idle and problem solved . Thanks

[independenttntn]

Succinct and to the point, THANK YOU! So many people drone on and on and on about stupid crap unrelated to the video. THANKS for NOT doing that. GREAT VIDEO!!

[dwaynecollins]

Finally an explanation that was easy-to-follow and he had my attention 😊

[oneilhall]

Perfect explanation and demonstration of how to get these adjustments done.

[leannenoske]

Thankyou Mike, Great explanation, adjustments made to the high speed, much better. Have a great Xmas and new year. Best Wishes from Tim in Australia

[HgMercurY]

Exactly what I was looking for, thanks

[RkyMtnWay]

Most helpful straight forward video. Skip the others. Thank you.

[kgt]

Mike, this is a great video bro....your demonstrating with sound and explanation all lends tremendously to the heightemed effectiveness of what you're communicating here. Great job, man.

[christopherturner]

Thank you for this explanation. Very useful and complete.

[samuelmenal]

My 85 head was spinning fast when I start I will lower it give thanks for your assistance 💯

[JessieWilson-bmsl]

Thank you so much. You're so helpful. Watching from Papua New Guinea

[sethh]

This is a great video if the unit already runs fine... but what about if it's not running and you need to learn how to adjust it from there? We should at least be given a start point. On most carburetors you turn them all the way in and then you turn them out a certain amount of rotations to get your start point, and then tune from there to make it better running.

[dandread]

Great video, simple and informative, I learnt a lot...thanks very much.

[Mike_]

Brilliant nice easy to follow guide! what a winner