Bar vibration

[bendjoseph]

I just installed a 25" bar on my Stihl MS391.  I noticed that when sawing logs about 15"-20" in dia, the tip of the bar vibrates back and forth.  Is this normal?  The 20" bar did not do this when it was sticking out.

[T Welsh]

bendjoseph, Yes, it pretty common, you will find the sharper the chain the vibe will be pronounced and the smaller the dia. of log does not have enough wood to hold the bar. I run a 36" bar on my 044 and it will do that if I cut small stuff, but I do not usually cut small stuff with a big bar,I get a smaller saw and match my saw to what I am cutting. my favorite saw is the smallest,lightest,sharpest saw that will do the job ;D Tim

[lumberjack48]

Loosen the chain, just a little 

Tim, we think the same, the smallest one that will do the job  8)

[T Welsh]

Loosen the chain, just a little 

Tim, we think the same, the smallest one that will do the job  8)

lumberjack48,I am getting to old to lug a big saw around anymore,the bigger the better mentality doesnt get it when climbing up and over and around while limbing and after doing it all day my butt is whopped :D. thats also the time when most accidents happen,the last one of the day or I,ll do one more is when they get you. 30 years of playing with this stuff does teach you a thing or two. Tim

[bendjoseph]

It was from the bar sticking out.  I also noticed it on my little 170.

[Al_Smith]

I run a 36" bar on my 044 and it will do that if I cut small stuff, but I do not usually cut small stuff with a big bar,

You know since you mentioned that I never would have never thought a little 70 cc 044 had enough grunt to handle that much bar . 

Well I'd heard of one on another forum and ran that thing which had been somewhat enhanced running a 36'" with a skip chain .I took that thing down about a 40" oak log just as slick as you please .Impressed me .

[T Welsh]

Al_Smith, The 044 is my favorite saw,its my baby ;D . Its on its 2nd top end and runs like all get out. I,ve been running 33rsc stihl full comp on it lately and I like it. just got finished ripping a sycamore down for quarter sawing,

My buddy asked if I wanted the 3120 and said no thanks,he said that wont pull through that with a rip cut

About a half hours time and a tank full of gas. The trick to it is the lightest and sharpest tool for the job in my mind,getting old helps to :D Tim

[Al_Smith]

Well they are indeed great mid sized saws .My fave is a modified 038 Mag .It would probabley handle a 36" but the longest I have in Stihl mount is a 32" which it handles in grand style .

Oh BTW that age thing doesn't get any better . ;)

[Clam77]

I've noticed the same vibration - I just changed the cutting angle to give the bar a full cut (ripping a log standing vertically) and it went away.

Wish I could find another 038M.... the older ones are getting harder to find around here.   :-\