Help with 346 rim/oiler

[paul hill]

I'm wondering if anyone has seen this or knows what might have caused it.

Was running the 346 when the chain began to slip. I thought maybe a clutch spring broke.

Took it apart at home and noticed the rim sprocket wouldn't move on the shaft at all. I pulled the clutch / drum and found the plastic oil pump pinion was stuck to the rim. Almost like they were melted together.

The clutch, drum, bearing and rim all look OK but the plastic oil pinion is shot.

I'm going to put a new oiler pinion, sprocket, bearing and drum on but I'm curious what cased this to happen?

 

[HiOctane]

Splines on drum are not stripped or the cracked tru the splines ?

 

[sunfish]

Never seen that? Running chain too tight? Chain too dull? Using chain brake too much?

 

[AVB]

I would say clutch slippage due to an overtighten chain.

 

[Duane(Pa)]

Had to be pretty hot to fuze them together like that...

 

[bigbadbob]

I have a 353 that was stuck together like that,, had to replace the gear and some other plastic that were melted,, not sure what the original owner did to it. The clutch springs were bad too, maybe the clutch was slipping and caused the meltdown.
I suspect ran with the chainbrake on also, but no proof.
Running good now.
BBB

 

[sunfish]

Starting a saw at high idle with chain brake on and letting it rev for a minute or so can smoke a clutch, melt the oiler gear & take the temper out of the clutch springs. I've also seem it melt the clamshell housings of lesser inboard clutch saws... I will never start a saw with the chain brake on!

 

[paul hill]

Splines on drum are not stripped or the cracked tru the splines ?

No, the splines on the drum look good.

 

[paul hill]

No, the splines on the drum look good.

Thanks for all the replys and ideas.

I don't ever use the chain break so I don't think it was on. I guess I could have bumped it but I never had to pull it back to the operating position when I took the clutch cover off.

Over tightened chain could be a possibility, but it was sharp for sure.

What if I had chain on the drum splines tightened up like it was on the rim? It would have been pushing the rim into the oiler pinion?
I remember the chain being a pain to pull off the bar but didn't look at it closely, just loosened it up a bunch.

Thanks to all the replies. I'm pretty sure its something I did from a case of head in ass but it bothers me that I can't find out exactly what it was.

 

[sunfish]

Well, I guess a chain being way too tight could cause it. Also with that much heat you might need to replace the clutch springs too.

 

[SawTroll]

Starting a saw at high idle with chain brake on and letting it rev for a minute or so can smoke a clutch, melt the oiler gear & take the temper out of the clutch springs. I've also seem it melt the clamshell housings of lesser inboard clutch saws... I will never start a saw with the chain brake on!

Just depress the trigger ASAP after the saw starts, and release the brake - it doesn't hurt much that way.

I don't like to start with the brake on either - but some times you just have to.

 

[nmurph]

Never seen that? Running chain too tight? Chain too dull? Using chain brake too much?

I would say clutch slippage due to an overtighten chain.

One of these.