MS170 x 2 fuel run issues, need repair advice?

[Okie]

I don't know a lot a about law boys or Homelites. But his saw has 2 piston rings and doesn't have reeds. It will get to the point where your going to have to pull the rope faster and harder to get it to start at all. I hope the carb fixes it but I doubt it.

Both saws up and running good. The carb was for the newer looking saw.

I asked the guy what he knew about the weak pull saw (120psi after 5-6 pulls of rope and saw will easily uncoil the pull rope by it's own weight) and he said he it was found laying beside road in road ditch.
That kinda explains why the end of the spark plug was rusty. I though maybe the saw had been exposed to heavy moisture or high humidity storage.
I also noticed it had what appeared to be green and white plastic chips on the saw instead of saw dust, like it was being used to cut plastic pipe???
It started up with a prime but would not idle until I turned the idle adjust screw several turns.
Starts easily and cuts wood good.

 

[a. palmer jr.]

Is that what you are going to try (no air box) with the walbro adjustable carbs? (still going to be a close 90 degree screwdriver adjustment or might be able to use just a driver screwdriver end and adjust by finger pressure???))

Give us a report back when you get one installed as to what you find, etc?

Okay, I'm reporting back: I got one carb in the mail yesterday and installed it on the 170. It started fairly quick but it took a long time to adjust it so it would keep running and idle. It seems when you run the engine at high rpm the thing didn't want to idle after that. I had to use a small set of pliers to adjust the idle even with air box off. I finally got it all adjusted but not sure if I'd recommend this setup to anybody. Might be better to just bite the bullet and buy a replacement from Stihl. I tried cleaning the original carb again and that didn't work either, couldn't get it to idle but it did run okay at high speed.

 

[Okie]

Okay, I'm reporting back: I got one carb in the mail yesterday and installed it on the 170. It started fairly quick but it took a long time to adjust it so it would keep running and idle. It seems when you run the engine at high rpm the thing didn't want to idle after that. I had to use a small set of pliers to adjust the idle even with air box off. I finally got it all adjusted but not sure if I'd recommend this setup to anybody. Might be better to just bite the bullet and buy a replacement from Stihl. I tried cleaning the original carb again and that didn't work either, couldn't get it to idle but it did run okay at high speed.

Was that the ebay Walbro? (around $15)

My OEM Stihl carb was a Zama C1Q 057A stamped on the carb. (The Q looks like a O on the carb stamp)
The Stihl part number is 1130 120 0603 and on the box is has the numbers C1Q-S57E @ $27.99.

When I called the main parts guy to order the replacement Stihl carb he wanted to know the casting C1Q numbers from my old carb. I did not ask why because I already had them on a note.
I think I seen at least two different Zama carbs when I was looking up the part numbers from the mediacat list and same replacement Stihl carb part # was for both types of Zama MS170 carbs.

Engine fired right up with a prime with the new carb.

 

[a. palmer jr.]

This carburetor was an off brand Chinese carb. similar to a Walbro. It finally seemed to run all right. I cleaned the Zama twice and the saw never did idle with it on so I'm waiting for the other carb. I hope it does better than the first but I imagine it won't. I soaked the second Zama for about 8 hours in carb cleaner but haven't tried it on a saw yet.

 

[Okie]

This carburetor was an off brand Chinese carb. similar to a Walbro. It finally seemed to run all right. I cleaned the Zama twice and the saw never did idle with it on so I'm waiting for the other carb. I hope it does better than the first but I imagine it won't. I soaked the second Zama for about 8 hours in carb cleaner but haven't tried it on a saw yet.[/QUOTE

I think you said you are flogging two of them. If the saw idling is just little bit squirrely on that one after a high rev, etc, might stick the chinaman carb on the other saw just to see if it acts same.
I've seen some saws with a leaking crank seal have erratic idle and some would even idle better or ok when the chain was removed or it's tension loosen indicating a clutch side crank seal leaking more as the chain was tensioned and the bearing still be good. (just little bit bad seal, kinda like being just a little bit pregnant)

 

[a. palmer jr.]

Already did that, I've switched carbs around so much I just about lost track. I already got rid of the 170 but the 180 doesn't idle right. Might still put the carb on it that I soaked for several hours and see if helps it any. I tried the new carb on it and never did get it adjusted so it would run right so I put it on the 170 and it worked so I left it on it and gave it back to owner. I thought I might be the owner of them for awhile but I really don't think I want either of them. If I get any saws smaller than the MS250 I'll just get another top handle. I already have several of them though..