McCulloch 250 Guide Bar Question

[Den]

Hi,
I've got a strong running early 1960's McCulloch 250. It is very clean and seems to have low hours. It has the original 20" solid nose bar on it.
My thought was to put a 36" bar and full chisel chain on it. I figured since it is 80cc and runs strong it should be able to handle it.
But someone cautioned me this might be a bit too optimistic... to think this saw will handle the 36" effectively. They suggested I would be better served with a 30" or 32" bar.

Is 36" too much bar for the saw?
What is the biggest bar you would run on it?
Back in the early 1960's what increments did McCulloch make their solid nose bars? (would be nice to have a period correct bar on it).
Did McCulloch even make sprocket tip bars for this saw during the early 1960's?

 

[Mac&Homelite]

You are not the only one to have this question, and I have first hand experience with it. Yes it will pull a 36" but it will not like it. I outfitted mine with a 36" 3/8 0.050 Stihl bar with very few modifications. Grind out the oiler, and add bar plate, as well as stud spacers. If you want any more pics on the modifications to run a Stihl bar, let me know as I have some more. I ran the chain tighter than I should have the two times I ran it, but I am still doubtful that it would havr run much better.

 

[Den]

Mac&Homelite, thats a nice looking rig.
Those 250's sound really nice and raspy, loud, and crisp.

 

[Mac&Homelite]

Thanks, it sure didn't look like that when I got it. I would be supprised if it is even broken in yet. Cylinder was minty. Has some running issues currently, carb box keep on filling up with fuel. I never tried it with a 20" on it, but I believe that is where it's sweet spot is.

 

[RandyMac]

36'' it will do.

 

[Mac&Homelite]

36'' it will do.
View attachment 607379

It will, but it doesn't like it, at least with the tune it can hold currently. Isn't that a super 250 pictured anyway?

 

[RandyMac]

Just a 250, it did okay in 42'' green spruce and you are right a 32'' would be easier on the saw.
However, if you file the chain to match the saw and the wood, you won't be disappointed.

 

[brandonstc6]

I have a super 250 with an 18” bar. That should be fun to run.


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[Mac&Homelite]

I have a super 250 with an 18” bar. That should be fun to run.


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What do you mean 'should be fun to run'?

 

[brandonstc6]

What do you mean 'should be fun to run'?

I can’t get it to fire, even on gas in the carburetor.


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[Mac&Homelite]

I can’t get it to fire, even on gas in the carburetor.


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You thinking what I'm thinking...No just kidding, I don't need another. I know even with mine it took quite a few pulls after I dumped fuel down the carb to get it to pop. Sure you got spark in it?

 

[heimannm]

You really need to decide what you want from than saw to select the best bar. 20-24" would be very good for most hardwood applications, make sure to keep the chain sharp. While Randy is correct that the saw will pull a longer bar, remember that the 250 is manual oiler only and with a longer bar you will have to be pumping almost continuously to keep the chain properly lubricated.

I am not aware of any sprocket nose bars during the time of the 250's but there were after market roller nose bars by General, Oregon, and others I'm sure. There were certainly later sprocket nose bars produced with the McCulloch logo printed on the bar that would only look slightly out of place on that saw.

Keep in mind that bars of that period were pretty wide, the large nose radius made it easier for the chain to slide around the hard nose bar tip.

Mark

 

[RandyMac]

Those old bars don't have much flex to them, I had a set of short boards that used hardnose bars to drive into the trunk.

 

[Den]

RandyMac,
Nice 250...especially like the full wrap handle, round muffler, and rubber grip on the handle. Doing the same thing to mine.

 

[heimannm]

I am pretty sure that is in fact a Super 250, those were standard features on those saws.




Mark

 

[brandonstc6]

RandyMac,
Nice 250...especially like the full wrap handle, round muffler, and rubber grip on the handle. Doing the same thing to mine.

My Super 250 has those features as well.


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[RandyMac]

That is a parts bin saw based on a nearly new 250, that had the driveside all but completely stripped.

 

[Okie]

I've got about 6 of the old McCullochs, 1-43, 46, 50's all running great and couple looks new.
I've got the original owners manual for one.

I think most of mine have around 20 to 24 inch bar and this seems just right for the big toothed chains in hardwood.

heinnman gave me lots of good info when I first started on the first one few years ago, re-building and adjusting the carbs, etc.

Also some good info over in the McCulloch vintage chainsaw forum
Some of them can be little tricky on the carb adjustments and have to be tweaked for good power under load. (and set the carb adjustments out little bit but if too far out (rich) the saw can start loading up under heavy full bar cut) I set them (the H jet) for 4 cycling out of the cut when piss reving and then the saw quits 4 cycling when fully into the cut)

After they have been setting for quite awhile I give them a shot of primer gas into the muffler and then full choke and wide open throttle when cranking. Couple will fire right up with the throttle at idle after they get warmed up at but most want full throttle starting.

About gas in the carb box you need to check two things , if it has the OEM gas line clamp at the carb fuel line connection is one source of a leak and next is the little cork gasket on the bottom of the carb and there are at least two different sizes of these cork gaskets. either one of these leaks will usually result in the saw not running right when in a heavy load cut.

The Tillotson HL63D, E, and A can be used interchangeable and use same kit and can also be used in place of the 87D, but the 87 D cannot be used to replace the 63A, D, E,
because the 87D does not have a choke butterfly inside the carb.


With proper linkages the Tillotson carbs can be used to replace the old bullfrog McCulloch carb. The Bullfrog McCulloch takes a high dollar kit and Tillotsons carbs kits are very reasonable and user friendly to work on. I've got a clean looking McCulloch bullfrog carb in my McCulloch parts box that I removed and installed a Tillotson so I would not have to eventually flog the McCulloch carb. (if anyone is interested in it give me a PM. (probaqbly could use a kit since it been in storage and not run in quite awhile.
Lots of good info about servicing the Tillotsons at their site.

Takes a real man to use them old heavy McCullochs. I mainly just use my old heavy McCullochs when I get a big tree down and just let the weight of the saw do the cutting, just holding the throttle wide open and let it cut.

Would put some of them up for sale but shipping a heavy saw is expensive.

I now use mostly Stihl saws for felling trees, the lighter Stihl saws are little easier to keep in vertical wood.

 

[RandyMac]

 

[Okie]

View attachment 608023

Get er dun!!!!!!!!

That one will make your oiler thump get strong. (or really weak and fall off))