Yet another Stihl 170/180 carb problem. This saw should have been recalled by Stihl and fixed by the dealers with parts that worked. It wasn't, so we all deal with it. 
Stihl Ms 170 Carb
- Thread starter djg james
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If I need a new carb, I was thinking about a cheap aftermarket carb. Half the price (did I say I'm a cheap SOB?). After all, they're both from China. Am I thinking wrong?
This saw worked great for years. I only had it in a shop once because it wouldn't start. Got charged $70 which I thought was kind of high. That's when I started looking for other shops then finally myself.Yet another Stihl 170/180 carb problem. This saw should have been recalled by Stihl and fixed by the dealers with parts that worked. It wasn't, so we all deal with it.
This latest round of problems resulted after setting around for a year. Still need to fix oiler problem.
Not really. I’ve done up several of those with the adjustable carb made in China.
But you must drill a hole thru the handle & housing as Stihl neglected to provide them.
SteveSr
Addicted to ArboristSite
The secret to putting these back together is to put the carb carefully in a drill press vice. That way you have BOTH hands free to mess with the innards.
SteveSr
Addicted to ArboristSite
You have a possible carb issue that you are going to troubleshoot by installing another questionable China AM carb?
The original carb that's still in there is stamped 'Stihl' and 'Zama' and 'China'. And the one I'm looking at is not a Walbro type:
https://www.ebay.com/itm/Carburetor...S180-Chainsaw-Zama-1130-120-0603/174149447090
So no new holes to be drilled.
Most of the time, I don't have feeling in the tips of my fingers (arthritis) but my duct tape method worked.
See post #27
Saw Fixr
ArboristSite Operative
For that small carb spring, to keep it in place, a drop of 2cycle oil will “glue“ it down so you can get everything else together, with less of a chance of it flying off.
Believe it or not, I was trying think of something I could use to do just that, without gunking it up. Didn't think of oil.
My opinion is that the almost non-adjustable carb that came with the Stihl 170-/180 chainsaw was designed to last a rather limited time. After that carb gave up, Stihl wanted you to throw the saw away and buy another. Poulan/Craftsman did the same thing 20 years ago. They figured that new carb replacements would then be available from the Chinese, so why worry?
Fitted a chi adjustable carb on a mates ms180,never looked back.
Heaps better saw.
Heaps better saw.
I have an OEM Zama brand new for the 170/180 saws if you are interested.
I would go a 215 or AM if I had to so it would have H and L adjustment. Otherwise, just kicking the can down the road for later.
encouragement, you are learning a lot, now know more than most sales people....
encouragement, you are learning a lot, now know more than most sales people....
Well I finally got around to putting on the aftermarket carb I got off ebay. No it's not a Walbro like some of you suggested; it's a Zama like was on the saw originally. I'm not one wanting to have to try and tune the carb. Just thoughtn it would be easier for me. It fired right up but after hitting the trigger to bring it back to idle, it remained on high and the chain was rapidly spinning.
So I located what I think is the idle screw, and I play around with it while the saw is running. I ran it out CCW and then CW, but the saw wouldn't slow down. I popped the air filter off and noticed the screw was actually reverse threads. The screw had completely backed out.
Next I screwed (CCW) the screw all the way in, replaced the air filter and restarted. Chain just was flying along.
Also at full throttle, it seems to scream more than before. I'll have to compare it to my Brother's MS 170.
Any ideas?
So I located what I think is the idle screw, and I play around with it while the saw is running. I ran it out CCW and then CW, but the saw wouldn't slow down. I popped the air filter off and noticed the screw was actually reverse threads. The screw had completely backed out.
Next I screwed (CCW) the screw all the way in, replaced the air filter and restarted. Chain just was flying along.
Also at full throttle, it seems to scream more than before. I'll have to compare it to my Brother's MS 170.
Any ideas?
Hi Have you run a pressure and vacuum test on the saw?
Have you run a pressure and vacuum test on the saw?No I haven't; I don't have that capability.Hi
To recap, the saw was running fine several years ago. I let it set and then recently tried to use it. It would run fine with the trigger locked on, but then would die when released or you would constantly have to pump the throttle to keep it going. New fuel filter and line. Everyone here suggested it was carb issues, so I took it apart and soaked it several times. Still the same thing.
Then they suggested time for a new carb. And now we're up to the point of the new carb not working.
Check to see that the throttle rod does in fact back out when you let up on the trigger. The spring on the carb is supposed to send it backwards. Something sounds jammed up.
BTW, did you notice how "easy" Stihl made it to remove/install the carb? Those mounting bolts are almost (but not quite) inaccessible. I wonder if this saw, resting at the bottom of their product line, was originally designed to be a throwaway.
BTW, did you notice how "easy" Stihl made it to remove/install the carb? Those mounting bolts are almost (but not quite) inaccessible. I wonder if this saw, resting at the bottom of their product line, was originally designed to be a throwaway.
SteveSr
Addicted to ArboristSite
The idle screw on this carb is simply an air bleed which is why it is a left hand thread. With it full CCW (all the way in) the saw should NOT idle but die. If it does run and/or run fast you likely have an air leak.
This sounds like an air leak. These are notorious for leaking around the pan gasket/seal.
