The chain scored a huge gash into the cylinder/jacket dust shield

[Stogierob]

Greetings, all...

I’ve a PM610 where the chain has scored a huge gouge through the cylinder jacket dust shield. This happened before i bought the saw. I’ve a new bar and chain for the saw and I believe the old bar was slightly twisted as i could never get the saw to cut straight. The old chain doesn’t show any particular signs of wear or abrasion, or a flawed link that would have caused this gouge.

Anyone got an idea of what happened? I don’t want to order a replacement for the part only to have it torn up again.

Thanks!
Rob

 

[Brent Adams]

Do you have bar spacer plates on it? Should have one on each side of the bar.

 

[Stogierob]

Based on the IPL, there doesn’t appear to be any separate spacer plates. The damaged part (part 16 - cylinder/jacket shield) and the (part 3) plate bar guide are shaped to hold the bar. There is a single washer (part 14) that is between the sprocket/needle bearing and the inner shield, but I don’t think this has much to do with that one washer. Parts list pict attached for reference.

In a chicken & egg situation, I’m thinking that the shield got bent. This let the chain come into contact and create the gouge. Once the gouge was there (or started), the shield continued to bend/flex toward the bar allowing it to gouge the plate even more. It could also be that the plate was installed incorrectly on the bottom, causing the chain to connect with the shield. I attached a second shot where the bottom of the shield is clearly out of alignment with the rest of the shield.

 

[67L36Driver]

That is the inner bar plate as such.

Check to make sure the washer #14 is present.

It all looks like an endplay problem really.

 

[Stogierob]

That is the inner bar plate as such.

Check to make sure the washer #14 is present.

It all looks like an endplay problem really.

I have the washer. As it fell onto my workbench before I could see where it was installed, I’m not sure it was in the right place. The IPL looks like it should be between the inner plate and the pin bearing cage. I think it was on the outside.

End play? That sounds like the bar was loose at some point? Seems like too much metal and too small a an area behind the bolts for the bar to flex.

Thanks
Rob

 

[67L36Driver]

Clutch drum endplay.

But check the crankshaft also.

 

[HarleyT]

Show us a pic of the chain and sprocket...

One of the chain,

and one of the sprocket teeth.

 

[Westboastfaller]

Chain throws do ruin guide plates then vibration will help split them.

They are important to keep the chain from derailing or coming off.
The outer one will take damage easier.
They are generally inexpensive.

 

[HarleyT]

Yeah, chain derailing is why I was curious to see pics of the chain and sprocket.........

 

[Stogierob]

The crank is solid - no wiggle at all. The clutch drum was very tight on the crank when i removed it. Again, no wiggle. Took quite a bit of convincing to pop off the crankshaft.

Picts... that’s both sides of the chain right after it was scrubbed after it came out of a rust-remover bath. It’s soaking in SAE50 right now. Not sure why as the new bar came with a new chain that is two links shorter (70 vs 72). Though, i am questioning whether the old chain is correct, or the new chain is correct, or if it’s just the bar/chain combo...

Rob

 

[Stogierob]

Chain throws do ruin guide plates then vibration will help split them.

They are important to keep the chain from derailing or coming off.
The outer one will take damage easier.
They are generally inexpensive.

Inexpensive, yes, but at $30/ea, plus i need spikes for the saw (didn’t come with any), I’m at $55 for parts for a saw that only cost me $85 (and may still have oiler issues). I want to make sure my repairs are one time repairs. I also don’t need the wrath of SWMBO if the total cost of parts starts adding up. I recently snagged a MAC130 that I’m just in the process of getting cleaned up. I’m hoping the chain and bar are adequate to survive the coming year. 1st born male is getting married and we’re going to have LOTS of extra expenses in 2020!

 

[HarleyT]

Needs a lot of work on the cutters!!

 

[Stogierob]

Needs a lot of work on the cutters!!

Please expound...

If you mean they look like hell and need to be sharpened, I’m working on that skill set. I can say that my dremel/cutter grinding bit got a workout several weeks back, along with the rakers. That dramatically improved things over what had been before. But i have a new chain to go with the new bar, so this old chain may not ever get used again.

Rob

 

[HarleyT]

If it is a new chain, I would get a new sprocket.

That model chain has some funky depth gauges, and all of the damage must be removed before it will cut well.

 

[HarleyT]

Here are a few that won't cut butter..

 

[HarleyT]

Putting a new chain on that old sprocket would be bad,
as it will quickly damage the bottom of the new chain.

 

[Stogierob]

Well, according to the IPL, that looks like the wrong sprocket hub anyway...

This is the part listed...