This is stumping me, 026 oil pump questions

[Millerhill520]

Hi,

I recently went over a bunch of Ms 260's. No problems building them, etc... I have done it many times. But, I took a pile of leftover parts and put a really old model together. This one wouldn't be one that would sell easy, so it's a gift to a family member. Cases didn't have hole in bottom for adjustable, 44 mm p and c, etc...

So I built it and it runs great, but when I threw a 3/8 rim on the sprocket today to mount a 16" bar, I noticed the chain turning as I spun the saw with the starter handle. So, common sense tells me Clutch issue, right? Well, here's where it starts to get interesting, and my afternoon gets chewed up.

I remove the e clip, and spin the drum. She spins free as can be. I remove drum, check clutch. Springs still Have white paint on them, nothing visibly broken. Good clean clutch. So I take it off, replace it with another clutch I have, and yes, it's used. But solid, not rattling, not loose, not spread open. Drum spins free as can be, put washer and clip on, and again! Locks her down and engages her. Chain spins and clutch feels engaged with saw not running when I turn the drum with hand, or the flywheel, hear engine turning top of course.

So I pop it off again, and take the best looking clutch, and replace the springs with new Oem springs. Put it back on, but of course this time I unscrew oil pump and pull and look to make sure everything is right.

From seal on up, here's what I got:

Small washer right above seal.
Metal crank driven drive gear.
Plastic non adjustable oil pump installed over it
Oil pump protection washer
Clutch, then drum rim washer e clip

So my question is, is the large protective washer scratched on this setup with the plastic non adjustable pump for oil driving reasons, or is it still part of the layers of an older 026? I looked at microfiche from the stihl shop, and I see images of 2 clutches, different carriers, but the order shows a washer and it looks like it's for all the pumps. I know the big washer wasn't on the large disc type metal one that was mainly in the 024, but what about the plastic one? Also, I just put a non adjustable in a newer 260, and I swore I had a protective washer behind that clutch on a rim driven drum setup? It's long gone now, so I can't check it to make sure. It was a 260 non pro, so I wonder if the parts were dabbed to accept the large washer, but the older 026 case, crank distance from seal to end wasn't?

Anyway, I ended up taking a little surface off the drum, where it sits on the end of crankshaft, and I slipped the item back on bearing, and washer, e clip went on and it spins free now. But the amount I removed from that rim driven surface was probably equal to the thickness of the large protective washer behind the clutch. Common sense tells me it is not used in this setup, but I do know it's function, and common sense says plastic oil pumps need protection.

So, someone on this site who takes the older 026's please tell me I am an idiot and need to remove that large washer so I can install my other drum that wasn't ground down to fit, or at least give me the easy answer to why this cost me 2 hours of my day?

One other thing. There's a chance, and I mean a small chance, the drum bearing isn't right. But, it fits tight on the shaft, there isn't a bit of slop on shaft to drum, and the only thing I see is it sat slightly lower than the face of the drive of the drum when on the saw.

Would love your opinions, but I'll check the modern computer system at the shop tomorrow and hopefully get an answer if someone doesn't know. Thanks guys

 

[HarleyT]

Here's a bulletin.

 

[Millerhill520]

Thank you.

I had a feeling that there was an upgrade made at some time. So, I must have had 3 clutches that were intended for the older style, or non clutch washer application.