Timberbear/Bar/Chain Questions

infomet · Feb 13, 2007

I took the muffler off my Bear today. There are two screens, one fine wire and one drilled metal. Should I take both out for max power? This thing was already the loudest saw I've ever seen!

The chain seems "lose" in the groove. I've seen threads about this, but don't remember anyone saying how to close the groove...hammer? Vise?

The chain also seems to lean more too one side than the other. Can I dress the bar with a file, or must it be ground? It seems like some sort of a fixture to hold the bar at right angles to a grinding wheel would be the way to go.

The detent on the brake has become tired and the handle flops down on its own. Is this common? I'm thinking I'll just file the notch in the pawl to make it hold better on the pin??

Should the sprocket be loose on the driveshaft? I haven't taken the clutch off, but can see a lot of play in the splines letting the sprocket move around quite a bit?

This Bear has very few hours, so I don't think I'm near the life of the sprocket.
Now on second chain and bar.

Thanks for any advice,

infomet · Feb 14, 2007

I looked around the shop for what might be useful for bar dressing.
I wound up with a 3/4" cylindrical Dremel stone chucked in the drill press and held in the hole in the table. It seemed to work well, but I'd prefer a harder stone or steel burr.

The groove in the bar measures from 0.05 wide at the back to about 0.06 in the middle. I'm still experimenting with methods to close the groove. have had some luck squeezing it in the vise,

mbopp · Feb 14, 2007

Is the oil pump working? It's driven off crankcase impulses acting on a diaphram & piston.
I've had some success on an old Homelite using a piece of .050" sheet metal as a spacer in the bar groove & beating it shut with a hammer & anvil.
The bar should be a D176 mount, they're are available on Ebay.
From what I hear filing the left & right cutters at different angles will cause uneven bar wear.
I actually replaced the muffler screen. I made one from a food strainer I bought at a dollar store.
The sprocket is an Oregon small spline on the factory clutch.
Sounds like a spring let loose on the chain brake. I think I've got a link to an IPL at home.
Here's where I get parts for my Mac 610 & 655:

http://www.fayettevilleequipment.com/McCulloch Parts.htm

GASoline71 · Feb 14, 2007

The oiler on those saws work great... when the are working. I replaced the oiler on my PM610 awhile ago and it made all the difference in the world.

I run a 24" Oregon Powermatch bar, with 3/8" .050 chain. Why try to beat the crap out of an old bar and make it work. Spend some cash and get a new bar and chain. If you are tryin' to keep it original lookin' with a Mac bar... start checkin ebay. There are lots of never used Mac bars on there. Plus the link mbopp gave will have Mac bars too.

Runnin' that thing with the bar and chain as you described is down right dangerous.

Gary

mark ormond · Feb 14, 2007

Iam sure you know if the bar is not all square it will cut like a dog
Oregon do a bar rail dresser part no27391 Closes the grove
And a speed bar dresser part no 90063 a bit like a surface grinder.
These part numbers are old ones
Mark