ms170 me likey! new pickup

rippinryno said:

Swapped out with a different size stihl brand chain and bar? How will I know by looking at the bar or chain what the pitch and gauge is? I know I can count links but how do I confirm the rest. Also not knowING for certain that this chain works with this bar how do I know that? I mean it cuts but it could be mismatched for all I know.

Does stihl make different pitch and gauge bars for the ms170? NOw i'm really confused, i really just wanted to buy a chain but nowi 'm worried. I think this chain is pico chain. It's got shorter cutting lines and when i was sharpening it, i noticed it to be different. I'm going to order the replacement stihl pico chain for a ms170 and i'm just going to hope the bar that is on this saw is original, i'm rather positive that it is.

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I don't know if Stihl makes any other bar for a saw that small but the 3/8 low pro which is pico

I imagine that's what it is. You mentioned you noticed a difference when sharpening it. Well the 3/8 pico uses a smaller file than what you use on the .325 chain on your bigger saw. So for the 3/8 pico it's a 5/32 round file. For the .325 chain it's a 3/16 round file. So if your files for your .325 chain are too big for the chain on the 170 you know it's not .325

To the best of my knowledge the 170s only option from Stihl is the 3/8 pico bar and chain set up. But I'm not a Stihl guy so just my gut telling me that. If it's a stihl bar that's on it I have to imagine it's the pico chain. It's very narrow chain

I've ordered many MS170 to MS250 carbs. They always look like the pic. Note the different styles prior to order.

I use the HF sharpener only on my Picco chains for my 170, the rest are 3/8 and I hand file them with the 2 in 1. HF grinder works good enough for the 170 chains IMO

Different sellers - Huztl, wangluo18, machinedoctors, globaltrading. . All were as pic-ed. I've never seen an AM carb where H screw isn't there. Takes 10-14 days from China. If you want sooner, try USA seller like Russopower.

Oh, I see what you mean - the ones with the tube on the metering diaphragm plate don't have H-L screws. I can't help there - never bought one of those, so I don't know what's different under that plate...maybe just a metering diaphragm?

CountryBoy19 said:

FWIW, to "carb-mod" the MS170 with a fully adjustable you need to do several things. #1 properly locate and drill the adjustment holes through the cover & handle of the saw. #2 Most importantly, you must plug the hole in the air-filter assembly where the "auto-adjust" port is. If you don't it will be direct dust intrusion point into the clean side of the air-filter and carb/engine. I turned a custom-fit delrin plug on my lathe and pressed it into the hole.

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CountryBoy shows the way.

rippinryno said:

Swapped out with a different size stihl brand chain and bar? How will I know by looking at the bar or chain what the pitch and gauge is? I know I can count links but how do I confirm the rest. Also not knowING for certain that this chain works with this bar how do I know that? I mean it cuts but it could be mismatched for all I know.

Does stihl make different pitch and gauge bars for the ms170? NOw i'm really confused, i really just wanted to buy a chain but nowi 'm worried. I think this chain is pico chain. It's got shorter cutting lines and when i was sharpening it, i noticed it to be different. I'm going to order the replacement stihl pico chain for a ms170 and i'm just going to hope the bar that is on this saw is original, i'm rather positive that it is.

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If they are both Stihl brand then they should be marked. The chain should have an ID number stamped in the drive links and the bar should have a part number stamped in it. From there you can look it up in the chart.

If it's a sprocket nose bar (most are) then it's fairly easy to tell the pitch on an unworn bar/chain because the chain won't fully seat in the nose if the pitch is mismatched. If you have calipers or some other type of precision measuring instrument you can determine chain gauge & bar gauge rather easily as well by simply measuring them.

I'll be honest, I don't know what Stihl makes for the small saws. Stihl brand bars & chains, while good quality, are a bit too pricey for my liking so I buy other brands. I just use the lookup chart to find the bar pattern that fits my saw, buy the bar, buy 2 sprockets, and 4 chains. FYI, general rule of thumb is 2 chains per sprocket and 2 sprockets per bar for most even wear.

rippinryno said:

Are you referring to the front sprocket? Long as mine look good and turn good I keep them.

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No, the drive sprocket. Unfortunately on the Stihl the clutch drum & sprocket are all the same so it's more costly to replace. There are aftermarket rim sprocket kits available if you prefer that route.

rippinryno said:

Anybody know if I can run a 56 link instead of a 55 link on this 16 inch bar? My store has the hus varna chains on clearance for $8. Everything matches up except it has 1 more link. I assume I may run out of adjustment sooner bit wanted to ask your opinions.

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Will he let you take the chain out of the package and see if it fits? If it does fit you will most certainly run out of adjustment sooner but I'm going to guess that if it fits you will already be out of adjustment (you'll have to run it out to the end just to get it snugged up).

Can't he just remove 1 link from the chain if it's 1 link too long? Maybe paying for that will be the point where it's no longer a bargain?

I try to save money in most ways possible.
There are few areas where I figure it makes no sense and I pay the regular price. Chainsaw chains is one of these areas.

Saws either are fitted with a spur sprocket that's one piece as part of the clutch drum (common on homeowner saws) or a rim sprocket ( common on pro saws).

The 170 is probably fitted with a spur sprocket as is I think all the clamshell Stihls up to the 390. But I could be wrong on the bigger Stihls like the 311 and 390 etc. Hard to describe how it looks worn but the spurs will be chewed up. You should be able to tell easy enough. The chain wont fit on it as easily and it probably will raise the drive links on the chain as you turn the chain.

As for buying chain ya the Stihl chains are more costly. I used to run them but I switched to Oregon. Little less money and the metal is a little softer I can sharpen them a little easier. But they don't hold an edge as long as the Stihl chain.

rippinryno said:

ok, that's what i figured, thanks woodhog. I figure if the saw is cutting, no need to replace a sprocket that's still functional. these drive sprockets are a 2 second job, remove circlip, washer, sprocket, replace, etc. the drum comes off with the sprocket as mentioned.

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The sprocket will "function" long past it's usable life. It will just cause issues. #1, a worn sprocket will increase chain wear, #2 A worn sprocket can make it rather difficult to get chain tension properly adjusted. Neither of those sound like a big deal but for the cost of a new sprocket I'll buy a new sprocket all day long rather than fuss with eating up chains and having to constantly readjust chain tension.

Here's a guide: when sprocket looks like this - replace it.



Bought this nonrunner Poulan 1800 and fellow had 2 chains. One was 56DL, one was 55 DL. When sprocket wore, he bought shorter chain. LMAO.

No grooves when new. Minimal swear shows side grooves. Moderate wear and top ridge starts dropping down - approaching replacement time. Look at the outer 1/3 of sprocket - what it all will look like new.