McCulloch Chain Saws

[Camperspecial]

This is the last saw to get running from a recent batch. Gas tank was super clean and hose was good. After a few primes it popped off. Idles and revs. Set aside a bunch of time to work on it before I got into it. Now what am I gonna do?

 

[heimannm]

I thought I would go ahead and drill & tap for 3/8" fasteners...the 5/16" drill bit just dropped right in...so I gauged the threads with a 10-24 screw and they appeared to be 24 TPI so I ran a 3/8-24 tap down each one and the threads cleaned up nicely. I am guessing the threads were somehow peened over which is why the 3/8-24 bolt would not thread in.

Next obstacle, the only 3/8-24 threaded rod I had on hand was pretty hard and impossible to tap the 10-24 threads for the muffler bolts so, I have some softer threaded rod coming from McMaster Carr. Hopefully it will arrive tomorrow and I can make some new inserts.

Overall the saw is rather rough looking and pieced together, but the cylinder is straight and true and the bore is right on spec. With a new thick ring piston installed I think it should be a strong runner.











Mark

 

[2broke2ride]

Hi guys, it's been a little while!!! Been totally buried in lawn mowers the last couple months!!! Never did get the Super 250 done. It is completely rebuilt and still acts the same way with 2 different rebuilt Tillotson carbs..... it won't draw fuel. I have rebuilt the flatback and going to try that next. This is exactly what it did before the rebuild.
I blew up project scrap heap SP81, It didn't even make 1 tank and locked up. Still need to take it apart and see what failed.
Currently in the middle of a rebuild on a PM55 for a customer. Looking for a set of 92517 rings.
Pics of the 55 and the really bad clutch side crank seal!!

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[heimannm]

I forgot to post that yesterday...threaded rod arrived...I made the inserts and six extras so I'll be ready for the next few...muffler is now installed. There is still some solvent odor in the fuel tank from the Red Kote so I'll wait another day or two before adding any fuel.





Mark

 

[heimannm]

Kevin - according to my notes the 92517 rings are thick rings for a piston with locating pins. Let me know if that sounds right to you, I can help you with a set.

Mark

 

[Brian Thacker]

I know that McCulloch used some 6.6 mm fasteners on the 600 Series saws, almost but not quite the same as 1/4-28...but I don't think they were so adventuress the the early days. The IPL calls for 10-24 screws in the muffler, I believe these big old saws came with inserts from the factory, I just can't figure out what size they could be.

Mark

Mark, Could there have been an insert into the hole like a ThreadSert? They use an odd thread and a odd size to fit into the hole to rethread it. Just a thought.

Brian

 

[heimannm]

I am not sure what it was intended to be but the 3/8-24 was a good match.

Mark

 

[sawfun]

This is the last saw to get running from a recent batch. Gas tank was super clean and hose was good. After a few primes it popped off. Idles and revs. Set aside a bunch of time to work on it before I got into it. Now what am I gonna do?
View attachment 910522

A Mac 660 is a great saw, being a super 250 geardrive. I can personally tell you how nice they cut. Randy Mac spoke highly of the Mac 660, so that should be strong testament.

 

[PogoInTheWoods]

Now what am I gonna do?

It is still a little dirty.

 

[Camperspecial]

There was supposed to be a video in the post of it idling, all cleaned up but didn’t realize videos don’t post here. When I’m back in the shop I’ll snap a pic of it.


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[heimannm]

48" roller nose bar with .404 chisel/skip chain installed. I will wait another few days for the Red Kote to cure fully, I ended up finishing the can (this was saw number 12 from that can) and it was a little thick in spots. Maybe we will just risk it and see if it will run when I get to Oregon next week.





Mark

 

[PogoInTheWoods]

There was supposed to be a video in the post of it idling, all cleaned up but didn’t realize videos don’t post here. When I’m back in the shop I’ll snap a pic of it.

You can post videos here by simply clicking on the 'media' icon in the composition toolbar and inserting an accessible link. YouTube works best.

 

[Syncop8r]

There was supposed to be a video in the post of it idling, all cleaned up but didn’t realize videos don’t post here. When I’m back in the shop I’ll snap a pic of it.

It played as just audio for me.

 

[Camperspecial]

BULLFROG CARBURETOR
I have nothing to work on at the moment so I'm going to pick up a 5-10 from a buddy. From what he described it needs carb rebuilt.
I've never rebuilt one of these so It'll be fun.
Car anyone provide a part number or direct me to the Homelite duckbill valves that will work here and a tip or two on installing them??
Also, the best source for a diaphragm.
Any general tips on this carb rebuild???
Thank you all in advance.
Rob

 

[Camperspecial]

It played as just audio for me.

Thats the best part.

 

[Woodslasher]

BULLFROG CARBURETOR
I have nothing to work on at the moment so I'm going to pick up a 5-10 from a buddy. From what he described it needs carb rebuilt.
I've never rebuilt one of these so It'll be fun.
Car anyone provide a part number or direct me to the Homelite duckbill valves that will work here and a tip or two on installing them??
Also, the best source for a diaphragm.
Any general tips on this carb rebuild???
Thank you all in advance.
Rob

There were (I think) 5 different versions of the bullfrog carburetor. Your best chance is to take your carburetor apart and compare the diaphragm to these photos. I believe I have the part numbers correct.

View attachment 896061

View attachment 896062

View attachment 896063

View attachment 896064

View attachment 896065

Mark

I'd compare your diaphragm to Heimann's chart, then look up the p/n on ebay.

 

[PogoInTheWoods]

Pretty sure this is where the McCulloch Carburetor link in Mark's sig used to go before the site 'malfunction'. After he reconstructed the thread the link changed and is now here.

https://www.arboristsite.com/community/threads/mcculloch-carburetors.122113/
Bear in mind it covers a lot of ground.

 

[Woodslasher]

I'd compare your diaphragm to Heimann's chart, then look up the p/n on ebay.

I just realized that pics don't show unless you click on the arrow that takes you back to his original post, fyi.

 

[Camperspecial]

I just realized that pics don't show unless you click on the arrow that takes you back to his original post, fyi.

I found them. Thanks!!


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[edju1958]

FYI,Bob Johnson has the BullFrog carb rebuild kits,BUT he gets kinda ornery when one tries to buy one.He'll try to even talk you out of it.He's got good prices,so just be persistent.