How to fix an anti vibe buffer on a MS170

Nutball

TreeHouser
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I need to fix the anti vibe buffer on a 170 that is right beside the cylinder. It tore in half a couple years ago, I wasn't there, so I don't know how it happened. Anyway it runs pretty well for having sat for 2 years with dead stink bugs in the open oil tank.

Am I going to have to take the whole thing apart just to fix that one little part? The cylinder is just going to have to move out of the way. How do I do that? I see 3 engine bolts on the very bottom of the saw, but the plastic case between the carb and cylinder and around the clutch looks like it will keep the engine from lifting out. Why do Stihl saws have to be so hard to work on?
 
Not having that model saw sitting in front of me, my suggestion is based on general saw knowledge and not this particular model. Typically the buffers will be between the engine and the handle/gas tank (one large molded piece). You usually have to remove the plastic covers first in order to get to most anything. I would not remove the 3 bolts in the bottom.
 
Most Stihls aren't hard to work on .You want a toughie try a Mini Mac .As far as the subject saw I've never even seen one .
 
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  • #4
The guy I work with uses them as his climbing saw, they are cheap and light. Hopefully someone here has taken one apart before. All I know for sure is that the engine has to come out unless I'm really missing some other option. It's like on an MS290 where to fix the orange cover's buffer you have to take the muffler off.
 
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  • #6
PICTURES

:(
 

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It either unscrews or simply presses into place. When you buy the replacement it should be obvious how it comes out. Looks like a 5 minute job.
 
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  • #8
Stihl saws have a plastic cap that locks in the rubber buffer, so the cap has to be pulled to remove the rest of the rubber, and to let the new one in. They can be hard to get in from one side only even without the cap in the way.
 
A little Vaseline and a short piece of whipping twine can help.
Also clean that thing up a little so you can see what you're doing.
 
Yeah get some compressed air in there first, clean out the work area...
 
The shock mount is already out except a little bit under the screw .First thing after you give the saw an amble amount of compressed air is to unscrew the screw
 
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  • #12
What screw?

I couldn't get some of the engine bolts undone, so I might be about done with this saw anyway. I'll likely break a lot of t25 bits trying to undo them.
 

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From the spare parts pics for the ms170, it seems there is no screw to hold the rubber for this silentblock, just the plastic plug for the outside and nothing on the cylinder side. The other chock absorbers have one plug on both sides.

Oh, the Tork's size is usually T27 on the Stihl, not T25. If the screw is just tight, it works, but if it is FT, like the cylinder's or the muffler 's screws, you wreck the screws and the bit.
 
Wipe a little Vaseline on that rubber grommet and pop it in. If you don't have Vaseline then a little dab of bar lube, silicone spray, anything to make the rubber a little slippery.
 
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  • #16
When I re-read what you said I see I missed your misunderstanding. Both sides have a plug, the cylinder side plug is the problem. Today the Stihl dealer guy I talked to couldn't remember immediately how it was done, but agreed the cylinder probably has to come out, $85 an hour. Then I got the idea to warm up the engine before taking the engine screws out to hopefully loosen them. One or two broke free, but the others were risking breaking my driver. My T25 bit has been holding up well ever since I broke it on a likely T27 and sanded it back flat to what is now probably more like a T27 since it fits so much better. Last resort would be stripped screw removing bit, then cut flat blade slots in to put the screws back in with. So, I'll try getting the block nice n hot and see if they break free.
 
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  • #18
It appears in good condition. The purpose of the plug is to lock the rubber in place. Also the rubber is shaped to push in easier than pull out with a rounded end and a straight cornered inner lip. The caps hold the rubber expanded making it likely impossible to pull out the rubber with the cap still in and since rubber expands when pressed it would be truly impossible to push a new one in. Without a cap in I have to poke a screw driver around the lip to force a new buffer in its hole.

If Stihl was smart they would have a spring screw into the cylinder so it wont break, and is super easy to replace. Unnecessary pain in the but, and might even cost 2 new saws worth of dealer shop time. I'm going to take my time fixing this one as I'm not really in to completely taking apart a saw, especially a dirty rusty ol thing.
 
Well first of all you need a good driver ,solid tip not tamper proof with a hole it .Those will collapse under strain .Good tool company ,Wiha of Germany who BTW make specialty tools for Stihl .A 6" T27 bit is around 8-9 bucks .It's made of vanadium steel,same thing car axles and wrenches are made of .Cheaper types are softer steel,those you can wring the end off of .Avoid ball end drivers . If you grind the end of a driver off it's junk because it will never reach the bottom of the screw splines .Best thing to do with that is keep on grinding and make a center punch out of it .

You have to have complete alignment on torx heads .They get full of oily sawdust and if you don't blow the shit out you will either wring out the outer portion of the screw or mill off the driver end .Then both are junk .I've never seen a torx head screw I couldn't remove .I've removed M5 and M6 from ABB robots and believe you me those are tighter than a bulls ass in fly time
 
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  • #20
I need to buy some new tools. The broken T25 now T27 bit is chipped, but it has not broken again yet, and I've tried. I'm surprised I didn't even break the screw driver. I ended up using a stripped screw remover and corded drill to get the engine bolts out and found they are some kind of lock bolt.

I also tore apart a 391 recently that ran not too long ago, and just quit. The compression has been low for a while. The best I could get out of it was a backfire through the carb. I'm a bit amazed how little a wore out engine does. I'd expect it to try to start but not this one.

Why does the exhaust side of the piston get so much abuse? It sucks there's no aftermarket cylinders.
 

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