Stihl MS 170 Chainsaw throwing the chain frequently

[CPTKILLER]

I have a Stihl MS 170 and use it for cutting brush around my small Central Texas Ranch near Gatesville, TX. It is a terrible chainsaw because it is unreliable. It throws a chain daily cutting brush usually 2" in diameter or less.

I had good success with Stihl products in Galveston County, Texas. As such I bought this small one based on that experience with chainsaws and weedeaters in a flood control district.

I took it back to Ace Hardware 2 or 3 times to get it worked on. Most recently, it has been throwing chains several times a day.

The mechanic reshapened the blade and verified that the chain tension was solid. He checked the blade also. I used it for two hours and then it threw a chain again.

Based on my experience, this is NOT A GOOD PRODUCT.

Any suggestions?

 

[TheFarmerInAdell]

Have you tried a new chain? You could have a bent tooth causing this.

The only time I've ever thrown a chain on my Stihl saw was due to lack of tension (my oops, forgot to tighten after bar change).

 

[Tompet]

Have you tried a new chain? You could have a bent tooth causing this.

If it is same chain being thrown repeatedly? An overlooked damaged drive link(s) a likely source, damaged chain tensioner and damaged sprocket another problem source, but tech would have readily seen sprocket damage and you noted tensioner was checked. Maybe a compromised/damaged bar rail, so that needs checked as well.

As quoted above try a different chain. The model of saw is not the problem.

 

[newbury]

I have a Stihl MS 170 and use it for cutting brush around my small Central Texas Ranch near Gatesville, TX. It is a terrible chainsaw because it is unreliable. It throws a chain daily cutting brush usually 2" in diameter or less.

I had good success with Stihl products in Galveston County, Texas. As such I bought this small one based on that experience with chainsaws and weedeaters in a flood control district.

I took it back to Ace Hardware 2 or 3 times to get it worked on. Most recently, it has been throwing chains several times a day.

The mechanic reshapened the blade and verified that the chain tension was solid. He checked the blade also. I used it for two hours and then it threw a chain again.

Based on my experience, this is NOT A GOOD PRODUCT.

Any suggestions?

Among all my other saws I've a 021 which is about the same size. The only times I've thrown chains were when the chain was slightly loose and a twig caught between the chain and the blade. I've only sharpened a BLADE one or twice. Or did you mean chain?

I would also suggest a new chain and a standalone Stihl dealer. Often dealers that sell other "stuff" like toilet paper and bolts don't have the expertise for chainsaws.

 

[M5farms]

its the chain or the bar. Replace both.

 

[Tompet]

Among all my other saws I've a 021 which is about the same size. The only times I've thrown chains were when the chain was slightly loose and a twig caught between the chain and the blade.

This is a good point too. Cutting small stringy brush and limbs for a couple hours as stated will loosen chain enough for small twig to be a problem. In this kind of cutting, maybe check chain tension well before the two hour mark and adjust as needed.

 

[Ford850]

If it's older it could have a worn sprocket too. I have an older well used MS170 and love the little thing. I did replace the sprocket and dressed the bar when I last replaced chains, but even before that it rarely threw a chain.

 

[Snobdds]

I would put money on a bent bar.

 

[Coyote machine]

Its definitely operator error and possibly the 'tech' working on the saw. It's definitely NOT the product, Stihl brand chainsaw. Doesn't matter where you bought it or use it. It needs the chain and bar, not 'blade' to be checked for damage(s) like pinched rail(s), bent bar, improperly sharpened chain, worn out chain, wrong size or gauge chain to bar sizes, etc.
Have a qualified Stihl dealer, who is stand alone store, as suggested look at it and give an estimate to correct the issues.
BTW, its a chainsaw, NOT a brush cutter. They make brushcutters too, hence the name brush cutter. :confused2:

 

[Deere Dude]

I had a small saw that throws chains especially when the chains are newish. It seems they stretch quite a bit and need to be tightened fairly often and don't let the chain sag.