Stihl MS170 vs MS180

[buzz sawyer]

I'm working on a 180 and see an additional plastic shield that goes over the carb before the air filter housing. I don't have the original housing. The housing from a 170 does not fit over the shield. With the shield removed, the 170 housing fits but the top port on the carb does not extend into the housing. Am I doing something wrong or are there two housings? This 180 has the side chain adjustment through the clutch cover but not the big adjuster knob. I may have found a correct one on ebay but am trying to confirm before purchase. Anyone familiar with this?

 

[buzz sawyer]

bump

 

[KostasVolos]

There are two air filter housings for both
the MS170 and MS180.

The oldest type is the one that accepts
air filters with a round opening .

The second type is for the stratified engine
of MS170 / 180 2-MIX .That one accepts
air filters with an oval opening .

I do not think that they are interchangeable.

The MS180 has an "air shield" ( black plastic ) that simply "almost clicks" in place over the carb .The MS170 lacks that shield.

I think you either have a MS180 2-MIX model
and got the older type of air filter box or
vice versa ,it's an non strato ,good ol'
MS180 and got a 2-MIX type of air filter box.

I place my money at the first case...

 

[SteveSr]

I'm working on a 180 and see an additional plastic shield that goes over the carb before the air filter housing. I don't have the original housing. The housing from a 170 does not fit over the shield. With the shield removed, the 170 housing fits but the top port on the carb does not extend into the housing. Am I doing something wrong or are there two housings? This 180 has the side chain adjustment through the clutch cover but not the big adjuster knob. I may have found a correct one on ebay but am trying to confirm before purchase. Anyone familiar with this?

I don't believe that the 2-mix (strato) version is available in the U.S. From my knowledge the MS170 and MS180 are the same saw with slightly different cylinders and pistons to account for the slightly different displacements.

 

[KostasVolos]

I don't believe that the 2-mix (strato) version is available in the U.S. From my knowledge the MS170 and MS180 are the same saw with slightly different cylinders and pistons to account for the slightly different displacements.

They also have different carburetors and
different connecting rod bearings .

 

[HarleyT]

There have been changes in the air filter housing, and filter, and carb/shield/etc..
Here is a pic of the latter changes.

 

[SteveSr]

There have been changes in the air filter housing, and filter, and carb/shield/etc..
Here is a pic of the latter changes.
View attachment 1078388

Interesting... So is the newer version a strato (2-mix) design or conventional 2-stroke?

I have only messed with the earlier versions and only when I couldn't avoid it!

 

[xtremez]

Not sure what year yours is but this is a 2011 MS 180 on my bench. Took it down for a fuel line because it was cutting out when felling. I added the i gasket on the intake side of the carb ( from an FS 90 ) because the original design is just the carb up against the plastic intake box for a seal

 

[xtremez]

The rest

 

[HarleyT]

Why they changed the saw a few years back, I'll never know. Here is the new style setup on the right. The one shutter on the left is from the older style.
When ordering parts, these differences are important.

 

[KostasVolos]

There have been changes in the air filter housing, and filter, and carb/shield/etc..
Here is a pic of the latter changes.
View attachment 1078388

Here in EU ,the left one is the non-strato version
( old style cover /air filter & af box ) ,while the one
in the right is the newer 2-mix model .

 

[stihltech]

IMHO the 170 was just a price point for an inexpensive saw. The 180 has just enough more power to make it useful.

 

[buzz sawyer]

There have been changes in the air filter housing, and filter, and carb/shield/etc..
Here is a pic of the latter changes.
View attachment 1078388

Thanks, I missed this post somehow. The 170 on the right looks like my 180. So far, just different AF housing and top cover.

 

[buzz sawyer]

Why they changed the saw a few years back, I'll never know. Here is the new style setup on the right. The one shutter on the left is from the older style.
When ordering parts, these differences are important.
View attachment 1078439

That's it. There is also a plastic shield that goes on before the carb - hance the need for a different AF housing.

 

[buzz sawyer]

IMHO the 170 was just a price point for an inexpensive saw. The 180 has just enough more power to make it useful.

I'm pretty impressed with the 170, haven't run the 180 yet, still waiting on the top cover.

 

[C George]

IMHO the 170 was just a price point for an inexpensive saw. The 180 has just enough more power to make it useful.

Yes I agree , after working on both I tell my customers to spend the extra $40 for the 180

 

[buzz sawyer]

More info and pics on this. Comparing my 170 to the new 180.
First two pics show the difference in the air filter housing. First is from the old 170, second is from the new 180. Third pic shows the black plastic shroud around the carb - that won't fit into the 170 AF housing. I took it off to try and the AF housing fit but the top carb port didn't extend into the housing.
I had trouble with cold starting this saw after it was all together. I found the choke wasn't closing all the way. After checking and re-checking the linkage, I found the choke plate was hanging up on the gasket - see 4th pic. I made the gasket opening bigger and it works fine. Just waiting on the correct top cover now but it runs great. P&C look really good but compression is only 125. I got the same reading on my 170 and a 171. My compression tester is the one I used on cars so the hoses might be a little long and this is a small displacement engine.