MCCULLOCH The official McCulloch thread

[fossil]

Speaking of 250's...
Is there any significance to a Belgian 250?
I was going through the 250's i have today to see if anything was worth saving and found the Belgian connection.

All I could find is that they were the first US chainsaw manufacturer to open a plant in Europe in 1963. There is at least one other Belgian 250 posted on CCE.se site but didn't see one with a label like yours

 

[Steve]

My brother came over today with the PM850 I gave him for Christmas 2016. We cut down a few trees and blocked them up. We'll haul them away and split them when I have more hands to help!

 

[heimannm]

Ingenious way to keep your chain out of the dirt. I may have to do something like that with my Struck mini dozer, I have the log winch available and with the proper ballast up front it will lift quite a bit.

Mark

 

[Steve]

It's also easier on the back! Not having to bend over alot.

 

[Al Smith]

Dead ash I assume?

 

[Steve]

Dead ash I assume?

Dead red oak. we have very few Ash trees here. Most of the Ash trees in my area where planted in city limits by the county workers. Lots of oak variety. Red, white, black, pin, and shingle. Lots of hickory too.

 

[cm76]

On the plus side, it should have a steel sleeve so you could bore it oversize if needed.

On the negatives, someone cut the AF cover, saw dust screen is broken (Bob Johnson has NOS, I have 3D printed replacements), muffler cover is missing, home made spike (now you may wish you'd have kept that small H&S), and something is going on with the compression release...could be just the anti-vibe mounts are broken but you should check it out.

Mark

I'm going to take a punt and say that this particular SP125 has been fitted with the later chrome bore cylinder. You can see that the cylinder shroud has been cut to enable the decomp valve access (higher than the original). This was something which had to be done to saws which had later model SP125C replacement cylinders installed. These cylinders came with the decomp valve located slightly higher than the original units.

 

[Al Smith]

It also could be built of components of several saws .You have no idea about the history of most saws this old .Seldom if it had much use would everything be as it left the factory whenever that was .Most 125's are west coasters from the era of old growth stuff .As such more than likely those that survived had seen much rough usage .

 

[Frank bierce]

I'm going to take a punt and say that this particular SP125 has been fitted with the later chrome bore cylinder. You can see that the cylinder shroud has been cut to enable the decomp valve access (higher than the original). This was something which had to be done to saws which had later model SP125C replacement cylinders installed. These cylinders came with the decomp valve located slightly higher than the original units.

Thanks for that info! Not very familiar with these. Looks to be a very likely reason.

 

[cm76]

Thanks for that info! Not very familiar with these. Looks to be a very likely reason.

No problem.

Here are some photos of a NOS McCulloch SP125C replacement cylinder assy - part No. 91110.

You can see the information sheet regarding the different location of the decomp valve, and the need to modify the existing cylinder shroud in order for it to fit the later type cylinder.

 

[Lee H]

Nice solid concrete info Chris. I remember several times McBob stating the different locations
were the 125 versus the 105. I had this argument with him several times but we all know how
stubborn he was. I have 125's in both configurations with original cylinder covers that have
not been modded.

 

[cm76]

Nice solid concrete info Chris. I remember several times McBob stating the different locations
were the 125 versus the 105. I had this argument with him several times but we all know how
stubborn he was. I have 125's in both configurations with original cylinder covers that have
not been modded.

Absolutely Lee. I have the 125’s with the different cylinder shrouds as well. I was pleased to see the evidence presented in this factory cylinder replacement kit as you mentioned.

Cheers

Chris

 

[Al Smith]

That is good info .I'd well imagine even finding a NOS replacement cylinder today would be rare as a hens tooth .
Regarding sleeving one ,as far as I know I'm the only one who has indeed not only done it but put the info over the internet .I used grade 50 cast iron but I suppose 4140 steel could have been used .However 4140 does not cut or finish as easy as gray cast .It's used for aircraft cylinders .
Now resleeving an engine is not a task most people would even try to undertake .If you could find a machine shop/engine builder to do it you'd have more money in it than the entire saw is worth .
An iron lined cylinder ,if it could be overbored then you have to find an overbore piston. Again not an easy task .At one time Wiseco and others could supply them and I suppose still could but the price would be very steep .Then again were all this an easy job anybody could do making it less of a challenge .As they say one mans poison is another mans meat .

 

[usmcbuckwild]

Hello all,

Recently acquired an 840 gear drive that i am attempting to get running. Cleaned it up (paint is faded pretty bad) but can’t get any spark. Checked all the wiring and it seems fine. Condenser? Coil? Any suggestions?

 

[Steve]

Clean the points. Even if they look good.

 

[usmcbuckwild]

Clean the points. Even if they look good.

I did, took time to verify the gap just to make sure.

 

[Sleeper]

I would be looking at the condenser then... or maybe the ignition coil... if it's cracked, then it may be bad.

Also check the on/off switch, make sure it works properly.

Another thing to make sure of is that everything is grounded well... if there is corrosion on the leg to cylinder mounting points for the coil, for example, it will not work right. Same for condenser to case, or points to case...

 

[usmcbuckwild]

I would be looking at the condenser then... or maybe the ignition coil... if it's cracked, then it may be bad.

Also check the on/off switch, make sure it works properly.

Another thing to make sure of is that everything is grounded well... if there is corrosion on the leg to cylinder mounting points for the coil, for example, it will not work right. Same for condenser to case, or points to case...

Did all that, even removed the wire to the switch just to ensure it wasn’t a bad switch. Cleaned all contact points and applied just a little dielectric grease to help fend off corrosion. Cleaned off all the grease and still nothing. Since parts are kind of scarce I don’t want to throw parts (and money) at it.

 

[PogoInTheWoods]

An 85358 condenser should work if you have a Mini Mac sitting around collecting dust. They were used on many Macs. Most any canister type condenser should work..., at least for testing purposes if nothing else. 61650 was also widely used. Here's a 50074 for 10 bux...

https://www.ebay.com/p/Ignition-Condensor-50074-McCulloch-Chain-Saws/1823999173

 

[usmcbuckwild]

An 85358 condenser should work if you have a Mini Mac sitting around collecting dust. They were used on many Macs. Most any canister type condenser should work..., at least for testing purposes if nothing else. 61650 was also widely used. Here's a 50074 for 10 bux...

https://www.ebay.com/p/Ignition-Condensor-50074-McCulloch-Chain-Saws/1823999173

This is the only Mac I own, but I will look i to what i can find with thise numbers. Thank you for the info!