We have about 15 fs94 trimmers, all but a couple old style primer. Of the 15 only maybe SIX will always run as they should. Rest have what seems to be fuel issues, will idle but will not rev up they just bog. a FEW of these will rev if you let them idle till they're just about to flood. I have worked on every aspect of the fuel system per stihl service bulletin, mostly w/o luck. I have thoroughly cleaned the carbs, the tank vent (the tube thru the air filter housing is too darn small clogs up). New style fuel filters help sometimes. I adjust the main jets way out, sometimes this cures them but only for a while then bogging returns. Dealer had one while it was still in warranty, got it back "OK" and it quickly started bogging again. Seems like a fuel priming problem. Sometimes the primer bulb won't pump, seems like the check valves in it are nfg. I kinda suspect the tank vent assembly too, I understand there are new style vents. We pull the muffler screens when brand new. We have had numerous ones where a clutch won't lock up, I used to replace them ,now I clean them in the bushings that the shoes pivot on and reassemble with a tiny bit of silicone grease. I stock clutches and the starter dog assy (engine side little black flappers) as they fail by just wearing down. I service fs94's for other landscapers and this bogging issue is commonplace and very frustrating because they leave my hands running great but come back soon bogging again. Noticed it on the web as well. Boss says WE WON'T BUY ANYMORE Thanks for listening.

I've seen a common failure in the recoils but different to what you describe. The carrier that engages the starter pawls (even new pawls) skips and chatters without turning the engine. I can't see the point of failure because it's hidden and my best guess is the engagement carrier has too much play from wear. Has anyone had this happen?

Thanks for the great vidio. My machine still stalls after I rebuild the carberator. Whats wrong wit my machine. Thanks.

I had 2 94's. Both had carb issues and would smoke and lose power when tipped sideways. Switched to Echo 2620's and love the power and reliability. However i love the weight of the Stihl and the grip and throttle, but Echo is a better trimmer. Chainsaws however, Stihl for life! Best in the biz.

Love the 94s. All I want to use for weedeaters anymore. Hate they went up in price recently. I've had some problems with the clutch on mine but it's from me moving the shield back to run the string longer. Haven't really had any problems with the pruners though. We've had probably 50 of them. The first thing you do is take the spark arrestor off the muffler. It tends to clog and makes it run bad.

Hi Wally! Loved the video. Great insight. I bought a second hand HL95, a very similar unit. It has a problem! The blades wouldn’t move when I got it. So, I replaced the piston rods in the gear box, which were clearly gone (the bearing cylinders were all over the inside of the gear box). Other than that, the gear box looked in good shape. After replacement, the blades still wouldn’t move. So I loosened the blade nuts & screws (which I know you said not to loosen, but just temporarily!). Then after detaching the cutter unit from the main shaft, I could turn the drive rod receptor on the hedge unit and the blades move ok. However, when I reconnect the main shaft, I initially get a small movement in the blades, then they stop moving. At the same time I get a bit of rattling noise from the shaft. I’m wondering if that it an indication the bearings on the base (fan unit) are also gone. Would love to hear your thoughts? Do you have a video at all of a fan unit - bearings replacement? Hello from Wales, UK!

Excellent review . I'm buying !

Great video, one problem I have on a fairly new machine is the articulated head won't move beyond 90°. The spring loaded sleeve and pin seem to be working fine, what do you recommend?

Are you sure you can't adjust these blades? Mine have too much play and the bolts are as tight as they can be. Do I have to buy a new header in this situation? The trimmer has done a lot of cutting.

Is the KM94R powerful enough to run a brush cutter blade? Great video, thanks

Hi Wally i have a km 94 combi its cutting out a lot while runnig idle. any ideas

I have a newer stihl hl 94 k and they suck also use them at work ....and there's constant engine over reving??

What kind of fuel do you recommend on the hl94 unit?

all trimmers need spark screens cleaned frequently or removed. Located on exhaust of the machine

Hey Wally could you do a review on the atom edgers? I love the atom edgers but always have problems with mine hahaha

Have you done a video on a trimmer that will idle but dies when gas is applied?

Where can I pick up a bare mine is broken

Do you like this KM 94 more than the KM 91?

i knew the plastic would rot at some point or fall apart.

Integrated Purge Bulb not a Primer , Im sure you know that…!

That bearing fails quite often, Ive seen the housing come in burnt from seizing and getting so hot they were smoking… $67 with the bearing , they make noise when they go bad

The enrichment lever sticks on , all the time