stihl ms170 bog down

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panic101

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enfield,ct.
i just purchased a stihl ms170.
the saw seems great
the only problem is at full throttle it bogs down.
if i rev it up and get the rpms up it will go to full throttle, but right off the bat if i do it will stall...
im not too good with carbs but i think the carb is the problem...
any advise?
thanks
andy
 
I recently bought a brand new one myself, and I had the same issue.

Get about 12 tanks through it or so and it should clear up. Don't push it real hard though (it shouldn't be pushed hard anyways, it's a 30cc saw, it doesn't really have a lot of balls).

The sprocket tip of the bar was really tight on mine. Take off your chain and make sure that sprocket is spinning freely. If it isn't, just lube it the best you can just cut little stuff with it - don't cut anything bigger than 6", I'd suggest just nipping away at limbs for quite a few tanks....

What kind of gas / oil you using?? Use 93 octane mixed 50:1 with NON synthetic oil for at least the first 10 tanks. Mine was running real smokey and stalling at idle as well. The dealer said that the Stihl synthetic was lubing the motor too good and the rings weren't getting hot enough to seat - resulting in some fuel to slip by and burn up in the muffler.

Check your spark plug and make sure it's clean and run that thing at high rpms for a few tanks in small wood.

That and also be sure not to lean into this saw. As I had stated, these saws rip, but don't have much torque. A 200lb guy burying the bar of a 170 in seasoned locust isn't the smartest of ideas.

If all that fails take it to your dealer and ax wat da dilly iz.
 
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I agree with WoodChucker. If you lean on a little saw like that you will end up with a snapped connecting rod.
 
I had a similar problem with my 180. Ended up having bad gas, Brought it to the dealer they cleaned it up and I dumped he gas and clean my can..
 
I recently bought a brand new one myself, and I had the same issue.

The dealer said that the Stihl synthetic was lubing the motor too good and the rings weren't getting hot enough to seat - resulting in some fuel to slip by and burn up in the muffler.

That's what I think about the synthetic oil too, don't use it until the rings seat. I had that proven to me the hard way on a new car engine.

Synthetic is synthetic regardless of the engine that is being lubed. Not many guys here will agree on that for a chainsaw though. I never use ultra on a new P&C, and it is not going to hurt the engine to break in on regular oil.:deadhorse:
 
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That's what I think about the synthetic oil too, don't use it until the rings seat. I had that proven to me the hard way on a new car engine.

Synthetic is synthetic regardless of the engine that is being lubed. Not many guys here will agree on that for a chainsaw though. I never use ultra on a new P&C, and it is not going to hurt the engine to break in on regular oil.:deadhorse:

I may be plain stupid but what is the difference between being brocken in in record time with dino oil or just taking longer with synthetic?

7
 
thanks for the advice. i will get into her tonight.
and yes ...i have been running 87 oct in it so i will try 93
thanks again...
 
I may be plain stupid but what is the difference between being brocken in in record time with dino oil or just taking longer with synthetic?

7

You are not plain stupid, and I could be in reference to the chain saw engine. The car engine that I referred to had not broken in at 18,000 miles. I can explain that if I need to do so.

As for the chain saw engine. The engine develops more power when the rings seat. Why delay that with synthetic? But I know that it comes down to IMO.
 
I gotta agree with murph on the synthetic thing. I just broke in a 200t and a 260 with amsoil mixed at 75/1 and no issues. In fact before amsoil I used stihl synthetic and never had any problems there either.
 
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