Oregon Speedcut NK on Stihl 034?

[Hundred Acre Wood]

I bought a 16" Oregon Speedcut narrow kerf bar (160TXLGD025) for my Stihl 034, along with some Stihl 23RSP chain that I finally found.

But mounting it doesn't work because the bar doesn't secure correctly even with the nuts fully tightened. The narrow bar leaves enough slop that it wobbles back and forth even though everything else is correct (tail mount, pitch, gauge).

Anyone come across this? I'm thinking some 8mm x 16mm .020 shims between the bar and clutch cover would do the trick, but I'm wondering if anyone else has a different solution?

Thanks!

 

[Dolkitafreak]

Couple washers is all you need, only shim it on clutch cover side, it’s not critical that they fit the studs tight, just make sure nothing is rubbing the chain and watch for clutch cover flexing when you tighten them up.

 

[huskihl]

If the shoulders of the bar studs are getting into the clutch cover, you could relieve the clutch cover with a larger drill bit

 

[Hundred Acre Wood]

Couple washers is all you need, only shim it on clutch cover side, it’s not critical that they fit the studs tight, just make sure nothing is rubbing the chain and watch for clutch cover flexing when you tighten them up.

Right, shim washers on the clutch cover side of the bar seem like a workable solution, as long as the bar stays flush to the powerhead for the oiler to work.

I got out the cheap calipers for a rough width measurement of the Oregon Speedcut bar and a Stihl bar to see the difference.





So that's about .040" difference which is approximately 1mm. That makes a lot of sense, since the Stihl 23RS Pro .050 gauge NK chain is about 1mm narrower than the Stihl 23RS .063 gauge. 1mm thinner chain, 1mm thinner bar.

I ordered a few 8mm x 16mm 0.5mm shim washers. Two of those on each stud should do the trick. I'll post a follow up in a few weeks.

If the shoulders of the bar studs are getting into the clutch cover, you could relieve the clutch cover with a larger drill bit

This is a good alternative, as the clutch cover is definitely bottoming out onto the studs. But I'd rather not alter the clutch cover if I don't have to, and the metal bushings in the clutch cover spin too easy for me to drill without some effort figuring out how to restrain them.

 

[Hundred Acre Wood]

Well after some monkeying around I resolved this in the most expensive way possible. Because OCD.

For posterity, the inside of the original clutch cover was hitting the shoulders of the bar studs. You can see why in these photos.

Original clutch cover:



There's no chamfer on the inside of those bushings for the bar stud to recess into.

Whereas the newer covers look like this (not my photo):



You can easily see the recess there to fit the stud shoulders.

The shims did solve the problem reasonably well, but it wasn't completely stable, turned out to be a PITA and I know I'd lose them.

So I went to the Stihl-er and got a new clutch cover. And a new 8T spur sprocket for the .050 gauge chain to run clean on because I needed that anyway. And he also finally got the bar in that I originally wanted too!

So many dollars later, my 034 celebrates its 30th birthday this year in style, looking like new!



Still have a hole in the clutch cover that serves no purpose (my chain adjuster is on the front), but now it's shiny. I'll keep the Oregon bar as a backup.

In the end, spent way too much, but it'll serve me another 30 years if I don't die first. And that 23RS Pro .050 narrow kerf is the real deal. It definitely feels a little faster than the 26RS .063 that was on there. Didn't test performance in any measurable way though so it could just be enthusiasm talking.