Stihl MS170 problem

[HappyCat]

I did a search for this but wasn't sure what I was looking for so I've decided to make a post.

I have a Stihl MS170 and this has been easy to start and run beautifully until now.

I was cutting a tree when the chainsaw died. I then restarted it without problems. It will start and idle but it won't rev or throttle up and the chain won't spin. It was then put in the garage for awhile. I then went to restart it. Had to go through the cold start position, then warm start, then placed in normal run position. Still the same. The engine just idles and I pull the trigger to give it gas and it won't rev up. Now the warm start position usually will send the chain spinning when it starts. This time the chain never moved even as I used warm start and the engine never revved up. I can move the chain freely across the bar with my hand so I know it's not stuck.

I know nothing about small engine repair. I've tinkered with lawn mowers and weed eaters but I know next to nothing about them. Any help would be appreciated.

 

[genesis5521]

I did a search for this but wasn't sure what I was looking for so I've decided to make a post.

I have a Stihl MS170 and this has been easy to start and run beautifully until now.

I was cutting a tree when the chainsaw died. I then restarted it without problems. It will start and idle but it won't rev or throttle up and the chain won't spin. It was then put in the garage for awhile. I then went to restart it. Had to go through the cold start position, then warm start, then placed in normal run position. Still the same. The engine just idles and I pull the trigger to give it gas and it won't rev up. Now the warm start position usually will send the chain spinning when it starts. This time the chain never moved even as I used warm start and the engine never revved up. I can move the chain freely across the bar with my hand so I know it's not stuck.

I know nothing about small engine repair. I've tinkered with lawn mowers and weed eaters but I know next to nothing about them. Any help would be appreciated.

Hi HappyCat:

I have an 8 year old MS 170. It's been as reliable as dirt. 2 weeks ago, the chain oiler pooped out. Like you, I know little about small engine repair. I futzed with my 170 awhile, but then took it in for repair. Estimate is under 50 bucks. There's just isn't much to a little 170 and if it runs at all, I just don't think it can be that serious (but I could be wrong). I suggest you take it to a reputable Stihl dealer and at least get an estimate on what it would cost to repair it, and go from there. In case you're interested, I just bought a new Stihl MS 290 Farm Boss. I have a post on it in this forum.
Click here: http://www.arboristsite.com/chainsaw/186750.htm

Don <><

 

[Cody@SPE]

Howdy HappyCat, Ive worked on several of the MS170s. First thing is first, make sure the chainbrake isnt locked. If that isnt the problem, next I would check the clutch, a clutch spring could be popped off, or the needle bearing located under the sprocket on the crankshaft is in good shape. Sounds like a definate clutch issue whether ot be the chain brake, bearing, or the clutch its self.. I can post a parts break down of the saw if needed.. Goodluck :smile2:

 

[Fish]

Go ahead and leave the bar/chain/cover off. But also take a 5/16 nut driver and remove the 2 muffler nuts, remove the cover and screen,
and try to start it again. We will go from there.

 

[JoshF]

does the throttle trigger still feel the same? have seen more than one 170 pop a throttle rod out of the groove. also have seen high side check valve leak and cause similar issue.

 

[HappyCat]

One of the first things I checked was the brake. I've popped it off and on each time just to be sure and it is not it.
The throttle squeezes just fine but when I squeeze it doesn't rev up.

 

[JoshF]

does the sound of the engine change when you pull the trigger? cough, gag, rev up just a little? or absolutely no change?

 

[HappyCat]

Absolutely no change.

 

[Fish]

Well..... If that is the case, take off the top cover too and look on the right side of the carb, and see what moves when you pull the trigger...

Should be easy enough to nail down....

 

[Fish]

Helll, where in Ky are you???
Bring it over with some beer.......

 

[Fish]

When I lived on Beaver Lake, I invited a few old friends down for a cookout and fishing extravaganza. My good friend came down the driveway
exclaiming that he had brought/bought a case of beer. I was down on the boat dock, and yelled back. "What did you bring for you all???!!!"

He was always a cheepass......

 

[HappyCat]

I'm in Floyd County right now. From the helpful posts here and youtube videos, I now have an idea of how I'll open this thing up and what to look for. I'll take pictures and post back on what I find this weekend. Thank you very much to everyone replying.

 

[HappyCat]

It took 5 minutes to fix. After fixing it, I can see how the bar slipped off. I was cutting sideways to slightly upside down while notching a groove. Added are a couple of pics to show what was the problem and the fix.

 

[Papashaps1]

It took 5 minutes to fix. After fixing it, I can see how the bar slipped off. I was cutting sideways to slightly upside down while notching a groove. Added are a couple of pics to show what was the problem and the fix.

I do y see pictures can you post what was the issue and fox. I have the same issue with my 170