Stihl FS 38 Questions & Answers

Hey Kym,
It uses unleaded - and yes, it needs to be mixed with two stroke oil, in the correct proportions.

Can you tell me what the mix should be please

Do not use ethanol based petrol E98 is best

If you have the owner's manual, it should show the optional trim heads that will fit your model.
Barring that, there are probably aftermarket heads with nylon or other plastic blades that would also fit.

I called into a Stihl dealer and they told me they have never hah them in and on the computer they will not be available till March 2020 I bought the attachment in March this year How can I get them.

no

Don't worry about locking the shaft do your self a favour and get rid of the unit (worst one ever made) it will save you time and money in the long run.

kind regards Pete an owner of one of these crap units.

There's a slot in the grass shield that you put something like a drill bit or nail into that engages a hole/slot in the thick steel "washer" that is just above the trimmer head.

BTW, I've been using our FS38 for 5 years with no problems other than wearing out the trimmer heads. The head I'm using now (#3) has the newer style head that has taller "collar" that comes up far enough to cover the bottom edge of the grass shield-which prevents early wearout from too-long grassy plants and vines (and the occasional piece of barbed or other wire or kudzu) wrapping around the head and jamming into any vertical space between the sheield and the trimmer head.
I always use a premium .095 line instead of the recommended .080 line Stihl wants you to use. (Only problem with that is you should remember to remove that .095 diameter line when you take it in for warranty service.)
For reference, I use the FS38 about 100 hrs per year most years a lot of it along creekbanks and fencelines, and a fair bit in tight quarters (hence the shorter, curved shaft) and most of it is on tall weeds-up to 6', vines, woody plants up to about 3/16" dia. and also on the dreaded KUDZU.
On this and the other Stihl's it helps to burn accumulated carbon off the screen of the screw in spark arrestor (if yours has one) any time the unit begins to lose power. I use a propane torch for that.

If I had to do it again, I might have opted for the FS40 or FS50 simply for a little bit more power, (all 3 use the same displacement engine, just tuned differently) but for anyone having rotator cuff issues or a recurring back problem (both, here) a little less weight is a GOOD thing.

You'd be better served mounting a dil$do on it but hang on then it'd be useful !

Yes it will. Almost.
(I use nothing but .095 line in mine.)

The original spools have 2 MARKED sets of line-holding slots-one is for .080 line the other one for .095 so that's no problem. The aluminum guide holes (grommets) in the trimmer head are big enough for the line to feed properly, so that's no problem.

The ANCHOR holes that secure the inboard end of the line MAY have to be drilled out slightly, to make it easier to insert the line, ESPECIALLY if the machine is typically used with .080 line before trying the .095 line.
A 2.5mm (.098 inches) or a #40 or 41 (.096 to .098 inches), or a 3/32" (.09375 Iinches) is what you'd be using. (The 3/32" bit has to be slid in and out a couple times to ream out the holes a few thousanths more. )

If by PLUNGER you mean the primer bulb, if it won't prime, then something is blocked with varnish which is what you get when fuel goes bad. Take it apart again, put aside the diaphragm and spray carburetor cleaner through all openings to (hopefully) dissolve whatever/wherever (it) is plugged. Don't spray that stuff on the diaphragm because solvent will damage it. Once you get it working don't leave it with old spoiled gas. Dump fuel between uses and always use fresh mix.
On the other hand if by PLUNGER you mean who knows what, I advise the same. Disassemble and try to clear whatever is blocked with solvent. Don't use compressed air because tiny parts can fly away.

Its a 2 stroke. Cheers

Yes it is a two stroke

I'm not sure but it definitely STROKES !

It would be very unusual to go through cord that quick and in theory it should feed evenly from both sides. The only thing I could think would be the line on the side not feeding is wrapped too tight so is being pinched into itself not allowing it to feed out which would make the "good" side to have to do all the cutting thereby wearing quicker.

Thanks Salty but I don't think this is it - it appears like the bracket things that keep the line in place within the drum are not doing their job so allow the line to unwind within the spool and feed out too quickly. I've taken it to the Stihl repair shop and they were less than useless and just sold me a new spool which does the exact same thing. It looks like these little brackets are meant to hold the line in place and stop it from unravelling but they don't???

Put twice as much chord on the bad side stupid !

Laurie,
You mean not bent at the end ?
Cheers Max

The shaft on this toy really needs a hit of viagra !

Two dogs, check cable mounts and end linkages . Probably the csbje us dry and seized somewhere inside the cable . Possible a seized solid throttle pivot or even the throttle valve stem seized in the carby . Trace the system from one end until you find where it's seized . Could Also be the cold start lock clip at the trigger stuck on . Cheers ! Global Grandad !

Sam, go to you tube type in Stihl SF 45 weedtrimmer lower bearing and flexidrive repairs . This model same as all of them to fix .
Just need to slide the tube housing forward enough to slide the square drive off . Then you can check the clutch on the motor and the cable for wear etc. ps the man on you tube is right . Stihl will want you replace the whole tube to get the simple phosphorbronze end bearing.
It is only held in p,ace by the screw that retains the clip for the cutting shroud mount . Simple job that end too. Watch the videos !
Cheers Max

First find a garbage bin then throw it in there and buy something !