McCulloch ProMac 700 Bar

[Randy Schneider]

Hi, not sure how to post to the McCulloch section, hoping this makes it there. Otherwise please let me know how to direct it. I don't see post thread in the McCulloch section. Anyways, I have a ProMac 700 which is a tremendous runner. It has a Oregon 28" bar on it which seemed O.K. when I got the saw. Now it is having control problems. I am seeing the bar flex all over the place on deep cuts when trying to cut my wedge. I have had the chain sharpened and it just doesn't seem to control. The bar does seem to have a lot of flex to it. I know this is a long bar. Is there a sturdier or more robust bar I can put on the saw? I also have a problem with the recoil. After the saw is run a few minutes, the recoil will not retract. I have had it apart and tensioned it with 3 turns, and cold it retracts fine. If I loosen the screws after warm, it retracts fine. Seems something is amiss with the assembly.
Thanks, Randy

 

[Brushwacker]

With your bar you could be cutting crooked for a number of reasons. Dull or improperly sharpened chain. Cutter size and angle and depth gauges need to be uniform, the bar rails need to fit the chain snuggish, not sloppy and surfaces even on the rail . Often a combination of some of this being out of wack with 1 or 2 being more prominent. If you know what you are doing often you can straighten and even things out if not to wore out. Make sure your bar isn't bent. Take it off and examine it visually from all angles and put the chain in the groove and check for a sloppy fit. 1 side may wear out faster then the other and turning it over may give it some more usable life . At some point it often is easiest and most practical to replace the chain, sprocket, and bar at the same time to prevent premature wear on singley replacing 1 at a time.
I haven't experienced your starter issue.

 

[Breckinridge Elkins]

How old is that Oregon bar? I believe the newer ones are somewhat soft. Could very well be screwed up/out of plane rails. They can be dressed and straightened as Mr Wacker says.
I love the PM700 and I agree it kicks butt. Then again mine is in 100 pieces right now waiting to be reborn. Maybe 28" is pushing it. Mine has a 24" Windsor bar on it.

 

[heimannm]

On the starter issue, my guess is the hook in the spring that is supposed to engage the starter pulley is deformed and when the saw is running the vibration causes it to disengage and unwind. You may be able to reform the hook, or tighten the spring itself to improve engagement with the pulley.

Mark

 

[Randy Schneider]

Thanks all,
I appreciate the help. I have reformed starter spring ends in my younger years. If I remember right I need to heat it up then bend. Then heat it up again, and quench it. Sound right? Any other bars I could look at that would accommodate the PM700? I just got a new chain to try, to rule out the sharpening aspect.

 

[heimannm]

It does help to heat the end in order to reshape the hook, if not the spring is very brittle and will crack and break if you try to rework it. Heating and quenching after you get it formed is optional in my opinion.

Mark

 

[Randy Schneider]

Great, appreciate the help Mark.
Randy

 

[Breckinridge Elkins]

Any other bars I could look at that would accommodate the PM700? I just got a new chain to try, to rule out the sharpening aspect.

D176 mount. Credit to Mike Acres for the pic.

 

[Syncop8r]

Check the rails with a square.