Author Topic: Large Frame McCulloch Bar Mounts.  (Read 1304 times)

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Offline Eccentric

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Large Frame McCulloch Bar Mounts.
« on: February 02, 2014, 03:10:52 pm »
This is a writeup I did on AS a while ago.  With things as volatile as they are over there, I decided to cut and paste it (with minor modifications) into the McCulloch thread here.  Was originally on page 756 of the McCulloch thread on AS.

Part-1

While switching bars on my 650 gear drive a while ago, I discovered some issues with large frame McCulloch bar oiler holes/slots and bar plates that I've never seen discussed.  Mark H, Al S, and the other McWizards probably knew it all already, but I sure didn't.  It all boils down to putting your inner bar plate against your bar to make SURE the oil holes and passages line up.  There are some cases (with certain bar tail and bar plate combinations) where things won't line up, and the chain will get no oil.

McCulloch (and Oregon) used/produced two different styles of bar plates for the large frame McCulloch saws (from the D-30 forward, as I understand it).  At least three different bar tail oiler hole/slot designs for these saws were manufactured for use on these saws over the decades.  Use certain early large frame McCulloch bars on a saw equipped with the later style inner bar plates (with two large symmetrical slots), and your chain gets NO oil.

Use a late style bar that looks like an enlarged 10-series bar mount, (no oiler holes, other than the elongated adjuster holes that also feed oil to the rails) with certain early style McCulloch and Oregon bar plates, and your chain also will get no oil.  First I'll cover the bar plates, then I'll cover the bar tail oiler hole/slot placement differences and the problems that arise when the wrong combination is used.


The late style bar plate looks like an enlarged 10-series bar plate.  Inner and outer plates are identical, with two large slots equally spaced, close to the centerline.  The early style inner bar plates are not symmetrical.  The early style plates have an inner and an outer (that can't be switched).  The lower adjuster pin slot is large (and in the same location as the lower slot on the late plates), while the upper (oil) slot is thin, but farther from centerline and moved forward in comparison to the lower slot.



Late style inner  bar plate on the right.  Early style McCulloch inner bar plate on the left.  Notice the narrower, higher placed oiler slot on the early plate.  You can also see that the early plate oiler slot lines up with the outer hole on the bar tail of this early style bar.  The late style plate oiler slot lines up with the inner, adjustment pin hole in this bar (and NOT the oiler hole).



Here's the late style plate on the left, with the early style Oregon plate on the right.  The oiler slot size and placement differences are easy to see here.



This is an early McCulloch inner plate placed over a late style plate.  Notice that the adjuster slots line up, while the oiler slots do not.


The oiler well cast into the bar mount pad on the large frame McCulloch chainsaws didn't substantially change over the years.  It is large, and accomidates both the early and late style inner bar plates.  A fellow can run a saw witout an inner bar plate and it'll oil all the various large frame Mac bar styles.



Here's the bar pad, showing the oiler well.  This happens to be a front tank Mac (a 550), but the pad/well design is basically the same for the top tank Mac large frame saws as well.



Here's a pic of the early style McCulloch bar plate on this saw.




Here's an early style Oregon bar plate on the same saw.  The profile of the Oregon plate differs from the Mac plate, but the oiler slot placement is roughly the same.



Here's the late style McCulloch bar plate on the saw.  It's basically an enlarged 10-series bar plate.



This is the back side of the clutch cover for this saw.  You can see that the area above the bar stud section is large and flat.  This allows the cover to seal off the oiler slot on the 'off side' of the bars (and on the outer bar plates), no matter which style they are.  This clutch cover has the style of bar tensioner that was used for most of the large frame Macs of the 1960's and 1970's.  The earliest saws (such as the D-30, D-36, and D-44) instead had a large tensioner screw in the bar pad portion of the fuel or oil tank (depending on whether it was a front tank or top tank saw).  This large screw had a VERY large head that fit into a 'thumbnail' slot cut into the bar (which you'll see in a few of my bar pics).  This tensioner style difference has nothing to do with the oiler hole/slot changes in bar plates or bar patterns.

Part 2 to follow in a minute or two....
-Aaron

For older saws:
Tune the H side so that it 4-strokes (burbles) at WOT unloaded and just cleans up when under load.
When you lift cutting load, the saw should immediately revert to 4-stroking.  Fine tune the transition point for the wood you're cutting.

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Offline Eccentric

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Re: Large Frame McCulloch Bar Mounts.
« Reply #1 on: February 02, 2014, 03:12:25 pm »
Part-2

Now on to bar tail oiler hole/slot differences, and the problems they can cause when used wit the wrong inner bar plate.


The early bar tail setup has two holes on each side. The more centered hole only functions as a place for the tensioner peg to fit into. The other, more outward hole feeds oil to the bar rail. A late style bar plate BLOCKS this hole rather than feeds it. The oiler slot on a late bar plate only feeds oil to the top adjuster hole when used on an early style bar. This hole isn't in use for anything (the adjuster peg is below the bar studs on these saws), and also doesn't have an oil passage which leads to the rail. This means the oil goes nowhere. The higher oil slot on the early style bar plate allows oil to go from the well in the bar pad to the upper hole in this style bar tail, feeding the rails. I have Oregon and McCulloch bars with this two hole, early bar plate ONLY pattern.

The later style bars have a pair of elongated combination oiler and tensioner holes.  When mounted on the saw, the bottom hole accepts the tensioner peg, and the upper hole receives oil and feeds it through a slot to the bar rail.  If an early style inner bar plate is used with this bar tail style, the oiler slot on the bar plate feeds oil to NOTHING except the side of the bar (as the slot is too high to feed the oblong adjuster/ oiler hole).  The chain will run dry.



A McCulloch branded early 'four hole' style bar on top.  Late "enlarged 10-series" 'two hole' style bar on the bottom.



An early McCulloch inner bar plate on the same early McCulloch branded bar.  You can see that the oiler slot lines up with the oiler hole.  You can also see the early 'thumbnail' cut in the bar for the early bar tensioner screws.  It's unneeded on most of the large frame Macs (which instead have the adjuster in their clutch covers).



Late style 'two hole' bar on top.  Early style 'four hole' bar on bottom.  On both bars, the solid black lines show where the early style bar plate oiler slot lines up.  Also on both bars, the 'hollow' black outlines show where the late style bar plate oiler slot lines up.  You can see that the early bar plate oil slot feeds the early style bar oil hole fine, but is too high for the late style bar oil hole.  You can also see that the late style bar plate oil slot feeds the late style bar adjuster/oiler hole fine, but is too low for the early style bar oiler hole (and only feeds oil to the 'blind' adjuster hole above the bar stud slot).

One other large frame McCulloch bar tail oiler style has a diagonal slot cut into it. This slot connects the inner hole of the bar (which serves as the tensioner pin hole when it's oriented below the bar studs) with the outer hole of the bar (which is the oiler hole that feeds a passage that leads to the bar rail).  Unfortunately, I don't have a picture of this style oiler slot, and couldn't find a bar in my shop which has it.  I've seen a few McCulloch labeled bars (and others) with this slot.  I have also seen other bars that were obviously modified to a variation of this style by an end user sometime in the last 40 years.  I didn't understand why............but now I do....


There's a few ways to use an early style 'four hole' bar on a saw that's currently equipped with the late style bar plates.

1)Swap on an early inner bar plate (McCulloch part # 61995). You can leave the late style outer plate on the saw. The McCulloch # for the outer plate is 61996. This plate will NOT work as an inner. It has the upper oiler slot as well, but that's not used when mounted on a direct drive Mac (or a gear drive with the bar mounted on the 'outer' possition such as my 650).  That plate was used as an inner on the large frame gear drives (1-80 series, 890, etc) when the bar was mounted in the 'inner' possiton, since they feed oil from the right side of the bar (instead of the left).

2)Cut/butcher your late style inner bar plate so that it has a higher oiler slot that allows oil to get to the upper hole on the two hole bars. That's spring steel, and hard to cut accurately IMHO.

3)Slot the bar tail between the inner (adjuster) and outer (oil) holes. Do this on the upper side, as it faces the saw. Do it for both sides so the oiler will work when you flip the bar for even wear. Looking at the tail of the bar with the bar upright and pointing away from your face (like it's your nose), the correct spots to cut are the upper left and lower right.  The bar steel is easy to cut accurately if you take your time.





Here's the same 'four hole' style bar from the earlier pics.  I've slotted beween the adjuster and oiler holes on the two faces where the oiler slot of the bar plate will sit.  Used a dremel tool with a reinforced cutting wheel.  Took my time, and carefully slotted it about 1/2 the thickness of the bar.  This gave a 'passage' (when the flat face of the bar plate is on it) about the same size as the passage that runs from the oiler hole to the rail.  The bar can now be used with both early and late style plates, as the last two pics show.

As for running a late style bar on a saw with early style plates..............you can either swap the extrememly easy to find later style plate on the saw, cut your somewhat rare early style plate (not my choice), or maybe radius the outer edge of the combo adjuster/oiler holes (on the top of the bar, as it faces the bar pad.......for each hole) so that the early plate slot will feed it.  I think I'd just get an easy to find/cheap late style bar plate to use with a later style bar however......

Why McCulloch switched these things around I haven't a clue. The bar pad casting on the saws doesn't appear to have been changed (other than the tensioner style change, and that doesn't affect the oiler situation).  My guess is to have their large frame bars and bar plates be more like the 10-series setup.  It does work well, although I'm confused as to why they didn't make those combination adjuster/oiler holes just a little bit larger so they'd work with the early style bar plates.  They must've figured that the dealers would be able to sell the customer a new inner bar plate to work with the new bar they were buying for their 5-15 year old (at the time) saw.

Sorry for the long, wordy posts.  Been chewing on this one for months.  Took some pics a few weeks ago when I had stuff on the bench to shoot.  I was also modifying that early 'four hole' bar before sending it to Keith to use on his Super 250 (with late style bar plates).  I'll be modifying my remaining early style bars in the same way when needed for use on my saws with late style plates (and that's most of my LF Macs).  My 650 came to me with a 'four hole' Oregon bar..............and no inner bar plate.  The outer was a late style bar plate, and the guy I got the saw from told me his father (the original owner) "traded in" the 36" bar/chain for the 24" Oregon B/C that was on the saw when I got it because "it was more handy" (ugh).   His father must've realized that the late style inner bar plate that his saw came with was not letting his saw oil the chain.....................and just ditched the inner plate rather than buy an early style inner plate (or modify the bar).  The bar I swapped on (prompting this whole mess here) was a late style NOS 31" hardnose.  I had a spare late style inner plate from a parts saw, and on it went.
-Aaron

For older saws:
Tune the H side so that it 4-strokes (burbles) at WOT unloaded and just cleans up when under load.
When you lift cutting load, the saw should immediately revert to 4-stroking.  Fine tune the transition point for the wood you're cutting.

Offline Eccentric

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Re: Large Frame McCulloch Bar Mounts.
« Reply #2 on: February 02, 2014, 03:13:28 pm »
You can also use D096/D196/UXL Homelite XL-mount bars (for an XL-12, SXL-925, etc) on these saws if you use the McCulloch "slim line" bar plate spacers (originally sold for large frame Macs for use with 'slim line' McCulloch bars).  You also must make sure that there is an oiler passage from the adjuster hole to the chain groove.  Some of these bars have that provision...........and others require you to modify the bar. 

You also must use the 'late' style bar plates that look like enlarged 10-series McCulloch bar plates (as outlined above).  That's in addition to the 'slim line' plates.  On the saw you start with the inner bar plate, then one 'slim line' plate, then the bar, then the other 'slim line' plate, and then the outer bar plate and the clutch cover.  Those 'slim line' plates keep the chain rivets from digging into things.  There is a possibility that the chain DL count will be different than what it was for the Homelite XL-mount bar when it's on a Homelite saw. 

The 'slim line' McCulloch bars were intended by McCulloch to be used on either the 10-series or large frame McCulloch saws.  When used on the large frame saws, they required the 'slim line' bar spacer plates (along with the original late style bar plates).  When use on the 10-series Macs, no 'slim line' plates were needed.................but stud spacers were.  The stud spacers were sold with the bars.  Still see them on ebay sometimes.  The spacers for the 10-series saws are the 'coil spring' type (needed to space up from the 5/16" 10-series studs to the 3/8" slot in the bar).  An 'S' type Homelite/Poulan stud spacer can also be used.


Here's Bryce Stott's listing for the 'slim line' plates.  Rob (Jockeydeuce) also had some of these listed on ebay recently...

http://www.ebay.com/itm/MCCULLOCH-BAR-SPACER-GUIDE-PLATES-125-105-STBX292-/360400117813?pt=LH_DefaultDomain_0&hash=item53e9856035
-Aaron

For older saws:
Tune the H side so that it 4-strokes (burbles) at WOT unloaded and just cleans up when under load.
When you lift cutting load, the saw should immediately revert to 4-stroking.  Fine tune the transition point for the wood you're cutting.

Offline DaveJ

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Re: Large Frame McCulloch Bar Mounts.
« Reply #3 on: November 24, 2015, 11:55:43 am »
Thanks for this posting. Very informative and well explained. I've been having trouble with a new to me Pro Mac 800 and finding a bar that will work.

Offline Al Smith

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Re: Large Frame McCulloch Bar Mounts.
« Reply #4 on: November 24, 2015, 06:55:18 pm »
Good info on the large bars .

Large 10 series as the 800 is will take any 10 series bars .Some Husqvarna mounts will work also . Fact if I remember it I'll try a few and report back tomorrow .

On that it seems the 16 and 20 inch Mac bars are easy to find.24 and 28" not so easy .32 and 36" are not easy to find at all .I can only imagine on the west coast were they were used with longer bars they might be easier to find than in the heart land in the hardwoods .Of all of the 10 series bars I have I only have 2 32" and one 36" .I've never used the 36" .

Offline DaveJ

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Re: Large Frame McCulloch Bar Mounts.
« Reply #5 on: November 25, 2015, 08:16:24 am »
I went back to the old guy who gave me the pm 800 and dug around in his garage. Found a 36" mac bar he apparently used with that saw. 36TMX63SN. Seems to fit. I'd really like to use this saw, but that's way more bar than I need. Sure would like to get around 24". Did they originally offer those saws with 16" bars? That seems way too small to me.

Offline Cut4fun .

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Re: Large Frame McCulloch Bar Mounts.
« Reply #6 on: November 25, 2015, 10:44:55 am »
@jon1212  betting this memeber has a NOS bar he could hook you up with.

jon1212  you really need to make a list and thread store here so people can buy those bars from you.  ;)

@Eccentric  knows these things well too. Aaron
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Offline Eccentric

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Re: Large Frame McCulloch Bar Mounts.
« Reply #7 on: November 25, 2015, 01:44:58 pm »
I went back to the old guy who gave me the pm 800 and dug around in his garage. Found a 36" mac bar he apparently used with that saw. 36TMX63SN. Seems to fit. I'd really like to use this saw, but that's way more bar than I need. Sure would like to get around 24". Did they originally offer those saws with 16" bars? That seems way too small to me.

TMX is Windsor's designation for the 10-series Mac mount (Oregon's D276).  Made for your PM800.  A PM800 is a 10-series saw and not a Large Frame Mac (250, SP125, etc), despite it being larger than a 10-10A or other smaller 10-series saw. 

The Large Frame Macs that this thread covers are a completely different series (with a completely different mount).  To confuse things, McCulloch did sell some 'slim line' bars that were intended for use on both Large Frame Macs (with the right bar plates) and 10-series Macs (with stud spacers).

The 82cc 10-series Macs (SP80/SP81/PM850/PM805/PM800/PM8200/DE80) were typically sold with 20-36" bars.  Doubt many were sold with 16" bars.  Jon1212 had several TMX and D276 bars in various lengths.  Probably still has some.  There are NOS and used bars on eBay too, including several 28" bars.   

You can also use an Oregon D176 mount bar on your PM800.  The D176 is Oregon's current 'multi fit' mount, intended to work on most larger Echos, XL-series Homelites with 5/16" studs, most older medium/large Poulans, and 10-series Macs.  IIRC, they still produce them in lengths up to 24".  They have been made in several lengths in the past.

If you adapt a large Husky mount bar (or similar) to a 10-series saw, be sure to cut oil channels from the adjuster holes to the chain groove.  That's how these saws oil.  D276, D176, and TMX bars all have these channels.  Like an A041 or K041 Poulan/Echo bar.  That reminds me................you can often use a K041 mount bar on a 10-series (or a D276/TMX on a K041 mount saw) without modifying anything...
-Aaron

For older saws:
Tune the H side so that it 4-strokes (burbles) at WOT unloaded and just cleans up when under load.
When you lift cutting load, the saw should immediately revert to 4-stroking.  Fine tune the transition point for the wood you're cutting.

Offline DaveJ

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Re: Large Frame McCulloch Bar Mounts.
« Reply #8 on: November 25, 2015, 08:15:22 pm »
Ah! Thanks and sorry for muddying up the thread.  :-\

Offline Eccentric

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Re: Large Frame McCulloch Bar Mounts.
« Reply #9 on: November 26, 2015, 03:51:58 pm »
No problem.
-Aaron

For older saws:
Tune the H side so that it 4-strokes (burbles) at WOT unloaded and just cleans up when under load.
When you lift cutting load, the saw should immediately revert to 4-stroking.  Fine tune the transition point for the wood you're cutting.

 

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