Electric chainsaw excessive clutch wear

[matzner]

Do you see any side to side motor adjustment in there?

I don't see any adjustment, but I think you've hit on the problem.   This is the assembled clutch:

   

This shows the drive gear and the spindle for the clutch:

   

The shows the wear on the failed clutch compared to a new unit:

   

There is a mm or more of unengaged plastic teeth when the new clutch is seated on the drive gear.  The tooth tips that were knocked off pretty much show the depth of engagement.  Since I can't see any way to adjust the spacing is this pretty much a lost cause or does anyone have a suggestion?

Thanks to all for your assistance,
DM

[Stwood_]

Does the motor gear have excess side to side play maybe?

[matzner]

Does the motor gear have excess side to side play maybe?

There's no detectable play in either of the shafts.

Thanks

[TDKPE]

Is this part of an anti-kickback blade brake system?  If so, how does it disengage the motor from the chain?  Or does it disengage at all (just a brake)?

[Roly]

Is this part of an anti-kickback blade brake system?  If so, how does it disengage the motor from the chain?  Or does it disengage at all (just a brake)?

I think Tom hit on something.   Normally a electric chainsaw does not have a clutch.    Make sure when the brake is activated it also kills the power to the motor, if not that could be the problem. If the chain is stalling from pinching that could also be a problem as I don't see anything that would stop the motor from trying to run. Roly

[matzner]

First, I need to correct my use of the work "clutch".  As others noted it is not a clutch as found in a gas saw, but simply a plastic gear that transfers power from the motor to the chain drive sprocket.

As far as I can tell two things happen when the brake is activated: the power is cut and a band tightens around the motor sprocket below the plastic gear.

Thanks
DM

[Stwood_]

A little research and this is a common problem. These gears in this link interchange with different brands apparently.
https://www.amazon.com/Lil-Red-Barn-McCu...B013S31ZUE

In one of the reviews, Lil Red Barns (which I have bought from) have a heavier gear than the factory gears.

5.0 out of 5 stars Fits My 16" Craftsman (Sears) Electric Chainsaw model 316-341070
Reviewed in the United States on December 6, 2019
Verified Purchase
I took a chance and ordered this McCullough part, as Sears lists this part as "discontinued" and no longer available (they like selling new saws!). It was a 100% fit and seems made of a heavier/sturdier polymer than the original, which had stripped out on the inside. My saw is Sears model 316-341070 purchased new in 2006. I actually ordered a second one so I would not have to worry about down-time for shipping if it happens again.

[matzner]

Hey Steve:  

Thanks for the effort!  My previous search on Amazon was for the cheapest part that would work - it was $9 compared to this one at $29.95.  The problem is that it is very difficult to discern if the more expensive part is any different. I read the one review stating that it was beefier than the original Craftsman part, but could not find anything else - not even a picture of the inside.  I guess I could order and return if it looks/fits the same way as the failed parts.

Again, thanks for the effort,
DM

[matzner]

On another note, to bemoan the state of retail distribution these days this a prime example of one part:many suppliers.  It does look like the bottom leftmost and rightmost might be a slightly different design, but no way to know if that is good, bad or indifferent.

   

[Stwood_]

Yup. Understand not really knowing if one is heavier or not.

I had a problem with an oiler gear on one of my Jonsered saws. After wearing one out on a 1983 saw I bought new, I found one and yea, it was china made. It stripped about immediately.
Research and measuring told me the new one was undersize.
I contacted LilRed Barn direct as they had them listed. They checked serial numbers and confirmed their gears were correct, and they were.
If you still pursue this, I suggest to contact them directly. They have their own website also.