Stihl MS-170 on/off/choke switch

[BigBlue1]

I recently acquired a Stihl MS-170 chainsaw. Switch was originally 'off' and I moved it to choke to start. Started fine. But now I can't get the switch to slide back to 'off'. Just seems to be blocked by something. Is there a trick to getting it to move to 'off'? I've been shutting it off by choking it, which is not how I want to do it. All the manual says about stopping the engine is "Move the Master Control lever to the stop position (0)". It also says under warnings "The Master Control lever / stop switch must move easily to STOP / 0".

Obviously it WAS working because it was in 'off' position. So I have to assume I'm doing something wrong. It just doesn't seem like this should be a difficult thing to figure out.

 

[WinterDeere]

I've been using so many Stihl saws for so many years, that if there's a trick, I must be doing it from muscle memory without even thinking about it. I don't think there's anything to it, other than just flipping the lever to the top-most position.

Have you pulled the air cleaner cover, to blow out any dust/chips, and verify there's nothing in the linkage?

 

[seville009]

Just a wild guess, but sometimes if you pull the throttle trigger while trying to move the choke lever, it’ll move (maybe)

 

[kozal01]

Pull the throttle and push it down.

 

[BigBlue1]

Pull the throttle and push it down.

"Push it down"... you mean the off switch? The 'off' position is upwards. Or am I misunderstanding?

 

[BigBlue1]

Tried the throttle idea. No combination of holding the throttle and/or the palm safety lever has any effect on the switch being able to move to 'off'. There must be some linkage jamming or disconnected.

 

[WinterDeere]

"Push it down"... you mean the off switch? The 'off' position is upwards. Or am I misunderstanding?

You're not misunderstanding. Ignore that post. "Push it down" is the wrong direction for off, on Stihl multifunction lever.

And no, you do not need to pull the throttle to turn off your saw. I don't even think it's necessary to depress the operator presence lever (palm, top of grip), but I can run out to the shop and check, if you'd like.

Both Stihl and Echo saws tend to have issues with linkage getting fouled up with sawdust and chips, which is why I had recommended pulling the air cleaner cover and blowing that whole area out with compressed air. I suspect that's the problem, unless something is physically broken or bent in your linkage.

 

[BigBlue1]

Thanks. That will be my next step to open the cover and check things under there.

 

[ruffdog]

The linkage for the choke lever is pretty simple so take a look at it. Maybe the metal spring for the detent is not positioned correctly?

 

[ruffdog]

Take a look at this video....it may be the same issue.

 

[BigBlue1]

That video looks like it may well be my problem. I'll check that out later today. Thanks!

 

[kozal01]

"Push it down"... you mean the off switch? The 'off' position is upwards. Or am I misunderstanding?

Winterdeere is right, I was misunderstanding the issue. My bad

 

[BigBlue1]

I opened it up and checked things. The issue is that metal 'tab' indicated in the video. Though it isn't out of place in my case. It just is refusing to slide up and over the contour of the plastic master switch lever. Instead, it appears to have too much friction and is just pushing straight back on the metal tab instead of riding up and over the bump on the lever. If I slide a screwdriver under the metal tab and lift it slightly the lever moves fine. So I applied some silicone lube to the contact area between the metal tab and switch lever. That seems to have done the trick for now. This saw isn't old or dirty so I don't think that is the cause. And my dad, who originally purchased it, never had any switch issues. Just my luck, I guess.

Thanks for the tips!

 

[xyz123]

Common things I see on stihls coming in is that metal piece on/off out of place or master switch popped out. Also the wire out of the mounting spot too.

 

[BigBlue1]

Common things I see on stihls coming in is that metal piece on/off out of place or master switch popped out. Also the wire out of the mounting spot too.

Everything looked to be in the proper place. It was just that as the black plastic master switch attempted to lift it wasn't sliding the metal tab up and over the bump, it was just pushing it straight back. My first thought was "did this metal tab get bent?" but there's really no way that happened. So I figured I'd try to lube the surfaces and let them slide easier. And it worked. This saw isn't that old and it has very little use and zero abuse.

 

[Sonny580]

I have that problem on all of my stihls! VERY poor design AND you have to be careful not to break off the tabs that the plastic cross shaft hinges on too when messin with them! They are hard to adjust but seam to do the job. Keep the area under there squeeky clean and some slick-um on the slides and they will work.