Stihl MS180 problems

[ttyR2]

A buddy thought he got a good deal on a Stihl MS180C at a garage sale for $75. Well...it only blows 110psi compression and even after going through the carb, it dies if you punch the throttle very much, and won't wind out. I'm thinking the really low compression is causing the problem. As cheap as this saw is, it's not really worth my time to pull the piston out and put new rings on it, is it? Not sure I feel like wasting my time on this cheap of a clam shell saw.

There's only one adjustment on the carb, and I'm not sure what it is supposed to do. Has a reverse thread on it. H or L mixture?

 

[cutforfun]

Try. Backing the screw out 2 1/4 turns and see if it runs. The 170/180 don't get much love but are good saws for the money.

 

[Thommo]

The only adjustment on the carby is the idle speed. Check the fuel hose for cracks between the carby and fuel tank because the usually perish so the carby sucks in air instead of fuel. The screen on the muffler can block up too.

 

[7sleeper]

With 110 compression I would at least take off the muffler and have a look for damage. If there is none I would put in at least a new set of rings inside besides checking the other things. They are nice saws and run very well.

7

 

[cedarshark]

+1 on pulling the muffler. I suspect a scored piston/cylinder. Your friend may get some bench time with a clamshell.

 

[buck futter]

A buddy thought he got a good deal on a Stihl MS180C at a garage sale for $75. Well...it only blows 110psi compression and even after going through the carb, it dies if you punch the throttle very much, and won't wind out. I'm thinking the really low compression is causing the problem. As cheap as this saw is, it's not really worth my time to pull the piston out and put new rings on it, is it? Not sure I feel like wasting my time on this cheap of a clam shell saw.

There's only one adjustment on the carb, and I'm not sure what it is supposed to do. Has a reverse thread on it. H or L mixture?

carb prob.
a saw with bad compression will be hard to start but fine once it gets up in revs. rings are needed for below 8000 rpm.

check for an air leak or carb rebuild.

 

[ttyR2]

I neglected to mention that yes, I checked the piston and there is some scoring. I already rebuilt the carb.

My question was more along the lines of whether this saw was worth putting a new piston and rings in it, considering the time required to open the crankcase.

 

[jughead500]

They aren't overly complicated to work on.I'm thinking thats the same frame as the MS250 so you may have several choices at a replacement motor for it not just the 170.:msp_wink:

 

[cedarshark]

Trying to retune for lack of compression and an air leak will not fix that saw. It needs to be pulled apart, probably piston replaced,new rings and seals and the cylinder cleaned up. Would I do it for a 30cc clamshell saw ? No. I would sell it for parts, try to recover at least part of the $75 investment and buy a used 026.

 

[tbone75]

Its needs a piston and rings for sure,really not that much money for that. Long as the jug cleans up ? Not hard at all to work on.
If it needs a jug too,look for a used one in the swap thread. Bet you can get one cheap ! For around 50-60 bucks you should have a good little saw. But you could also buy a good one around here for 125-150.
Myself I would just fix it,then you know what you have.
May take 4 hrs to tear it down,clean it up and back together. Some guys can do it in a hour ! I am a little slow. LOL

 

[Stihlofadeal64]

They aren't overly complicated to work on.I'm thinking thats the same frame as the MS250 so you may have several choices at a replacement motor for it not just the 170.:msp_wink:

It is not the same frame as the MS250.

 

[tbone75]

Just thought of something else. I think its the 018 has a 8mm pin and the MS180 has a 10mm pin. Got to be sure what piston you need. I am not 100% positive on that ? Just know for sure there are 2 different pin sizes.

 

[ttyR2]

Oh trust me. I have better saws. I'm quite happy with my 026/036/046 saws

 

[danielr]

With 110 compression I would at least take off the muffler and have a look for damage. If there is none I would put in at least a new set of rings inside besides checking the other things. They are nice saws and run very well.

7

Their supposed to have 110psi and even if wasn't correct 2 stoke engine's have compression reading depending on the temperature then it's going to have a low reading if you ran it for a while and then was to check it then the reading will be higher

 

[rupedoggy]

Their supposed to have 110psi and even if wasn't correct 2 stoke engine's have compression reading depending on the temperature then it's going to have a low reading if you ran it for a while and then was to check it then the reading will be higher

Let's see you just joined today and responded to a ten year old thread so I guess the mis-information doesn't really count.

 

[hwrdpromac7900]

Explain the mis-information. Share your knowledge.

 

[rupedoggy]

1. Their supposed to have 110psi
2. 2 stoke engine's have compression reading depending on the temperature
3. if you ran it for a while and then was to check it then the reading will be higher

 

[hwrdpromac7900]

Explain why it's mis-information. Help danielr to understand and learn.

​

 

[KASH]

What piece of the puzzle am I missing?
Kash

 

[stihltech]

Dump the compression gauge. Hold it by the starter handle. It should stay up or go down slowly. Then pull the muffler to check condition. A visual inspection of components is much more important.