MacCulloch 1-41 (I Think) chain adjustment ?

[Mike Ray]

Bought an old mac 1-41 at least It looks like another one that was in this collection that is being sold.Chain was super tight and I believe it was keeping motor from turning over, anyway took bar and chain off , but when I tried to put it back on couldn't get it to tighten. I haven't seen this system before ,where head of adjusting screw fits into slot in the bar. Finally figured out problem had been tightened on edge of slot on screw head . and screw now won't stay in contact with slot. Has any of you seen this before and what was your fix. I'm thinking square up slot and screw head.

 

[Maintenance supervisor]

i believe that the 250 pin type adjustment clutch cover will fit that saw.

 

[heimannm]

The screw with the oversize head was a common bar adjust technique on many of the early front tank and top tank McCulloch large frame saws. Depending on the model you either had to reach way down in there to reach the screw, or there was an extended shaft coming out to the front of the saw to make it easier to see and adjust.





If either the head of the screw or the edge of the slot are worn they can form a sort of bevel which will add tension to the chain when the bar nuts are tightened up. My guess would be that someone got tired of the chain stretching (since they didn't oil it enough in operation) and decided to make it tighter so it would "last longer" before the next adjustment.

If the screw head and the slot are not properly aligned when the bar is installed the screw may have been bent, keeping it from engaging in the slot, try rotating the screw 180 degrees and see if it changes the fit. I should be able to provide you with a different screw if that is what's needed. See if yours is fine (1/4-28) or coarse thread (1/4-20) as they used them both on different models.

That system was very hard to make work with any sort of inner bar plates installed.

Some later clutch covers were made to put the bar adjust screw in the cover, in which case you just need the different screw and bar adjust nut. Many of the older covers did not have any provision for the bar adjuster.



By the time they got to the 250 the bar adjust was in the clutch cover.



Mark

 

[Mike Ray]

Thanks for the info the edge of the slot was pushed in and I don't think screw head was getting to full depth I took a couple punches and tapped the edge of the slot back square and the screw head has a better contact area ,it is a hair pulling experience trying to get the bar/guide plates lined up, can you leave them out I'm not going to cut wood just want to get it running for the fun of it, and don't want to throw the chain. Thanks again ps screw doesn't appear to be bent.

 

[heimannm]

The bar plates are often called "bar protector plates" but in fact they are there to protect the case and the clutch cover in case of a thrown chain. The saw will work just fine without them and it is certainly easier to get the adjuster engaged in the bar without them, you'll also gain a few thousandths engagement of the adjuster screw (head) with the slot in the bar.

Mark

 

[Mike Ray]

Thank you very much for the information I"M getting into old saws late in life. Found this one at a estate sale sort of , have lots of old saws widow is selling them off, her husband supposedly has all the saws on lower level running (100+) that many or more in loft he had't worked on.David bradley, Mac's, Homelite, Mall and I am Sure others If you want I will call her for you an get you hooked up with her , saws that is. I bought a dog compared to the others, but I didn't want to have much money tied up in a saw I'm not going to use.