Clutch inspection

[hosocat]

I have one of those little 25cc top handle Chinese saws off of ebay. It's actually been a pretty good saw for my use, non commercial. I've used it for about 3 years.

It seems like the clutch is starting to slip more frequently when I pinch the blade or bury it too deep into a cut. So I decided to take it apart and inspect the clutch, which I haven't ever done on a chainsaw. When I looked at the clutch plates I discovered they are metal. I was expecting to see some kind of wearable friction material.

So my question is, how do you determine if the clutch plate needs to be replaced? It doesn't look to me like there's any material that can wear down.

 

[Mad Professor]

It's the springs that usually give the problems. Make sure they retract the shoes all the way. But that causes clutch to engage at idle, not your problem

If it's slipping the parts might be glazed. Roughen up the shoes and the inner drum surface with some 80 grit sandpaper. Give the bearing a dab of grease while you are in there.

Got pictures? We love pictures.....

 

[hosocat]

Thanks prof. I'll take some pics. Need to take it apart again first.

 

[hosocat]

Here are some picsbefore I sanded mating surfaces. I went ahead and sanded and greased bearing like you suggested. Don't know if you can see anything in these pics or not. I haven't tested it yet to see if that improves things. It still cut okay, I just had to be careful not to put too much pressure on it or the chain would stall.

 

[HarleyT]

Let's see some pics of the chain, and of the sprocket's teeth!!

 

[hosocat]

They aren't worn to any extent.

 

[Philbert]

The metal clutch shoes can wear. More commonly the skirt of the clutch cup itself enlarges/ ‘stretches’. These are by amounts that are hard to see, but could be measured with precision tools.

If the problem persists, I would try replacing the clutch cup/spur sprocket as a simple thing to try.

Philbert

 

[Old-Feller]

Looks to me like it got a lot of "Ball And Chain" Oil all over it. The drum looks way out of round too! Measure it across at 6 points and record it, It looks oblong.

 

[HarleyT]

Let's see some pics of the chain, and of the sprocket's teeth!! If this is one of your teeth, show us the rest.
That may contribute to your problem.

 

[skeet88]

Let's see some pics of the chain, and of the sprocket's teeth!! If this is one of your teeth, show us the rest.
That may contribute to your problem.
View attachment 988454

Good eye Harley!Just reinforces the statement “we need pictures “.

 

[ChillyB]

Help out a rookie. What is it about the chain I should notice?

 

[skeet88]

Help out a rookie. What is it about the chain I should notice?

The chain has a broke cutter next to clutch sprocket in picture.

 

[skeet88]

Hopefully you can see where I circled the broke cutter.

 

[HarleyT]

I am in Kentucky.
We know about missing teeth.

 

[skeet88]

I am in Kentucky.
We know about missing teeth.

Bout fell out of my chair!

 

[Mad Professor]

I am in Kentucky.
We know about missing teeth.

Is that why they call it the Tooth brush, not the Teeth brush?

 

[link]

...

 

[TRTermite]

Hopefully you can see where I circled the broke cutter.

The chain is also dragging the bottom of the tie straps like the sprocket/rim is about gone(Done fer) and/or the bar nose is bad.

 

[HarleyT]

Yeah, I like to see what we are trying to give advice about, makes for much better responses.

 

[hosocat]

Thanks for the observations, guys. Yeah, skeet. I had not noticed that broken tooth. Looked closer and saw that 4 teeth were broken off. That might explain why it was getting hung up in the cuts. That's the original chain, and some of the teeth were getting really tiny. I checked the drum with a micrometer and it still seems to be round. Guess I'll slap a new chain on it and see if that clears up the problem.