Mcculloch Chainsaw Eager Beaver Ii Ignition Coil

John,
Thanks for your comments. Yes, if I was in business, it would be hard to justify the time spent-you could never make money on it. This design is really a pain since you need to totally disassemble it to do anything. The carb and coil are the last parts to be accessible. As far as this particular saw, I don't have much into it, it was basically free. It ran intermittently a few days ago, I made a few cuts with it with good power and then dead with no spark. So at this point, I have a pile of parts and it gets one shot to go back together, then scrap. I'll work on it between jobs on the IROC-(currently pulling the engine).
Incidentally, I agree about the electric tools. That will quickly become more mainstream as prices come down. Before my retirement, I was a hybrid / electric powertrain engineer for the last 15 years. What we can do now with variable frequency inverter drives, microprocessors and lithium batteries is quite amazing. The lithium cells are a great enabler, although still much less power density than gasoline. Small power tools can run with simpler control logic most of the time and are fast becoming a great alternative.

Dan
 
i have a big US made Mc Culloch ,bought second hand in the 70s ,its cut up lots ,had a tree fall on it and bust the casting,tank split,but it still goes......unfortunately ,it now belongs to an old man,who is better off with a tiddler.which is what I use now.......anyhoo,the greenies running the country now will throw me in the slammer for cutting down trees.
 
One of the hardest things I had to do in my business was when older gentlemen brought me big chainsaws that "wouldn't start". I'd clean them up and get them running good, then they would take them home and bring them back complaining that they still didn't start. I'd start them up and patiently explain that it wasn't the saw....

Electric was a good solution for them.

John
 
Mine starts easy ...I use spray can ether......cuts straight thru the 2/s oil blocking the carb..........Biggest fault is it runs at slow revs and makes a lot of racket ,the old time chainsaw bark that the greenies hate when it hunkers down into a big tree.
 
Petros,
I found your post while searching for a coil for a similar saw. Your solution seems very good. The coil on my saw appears to be identical. I know this thread is rather old, but could you tell me if your work was successful? If it was good, I would be interested in knowing what model or part number of Husqvarna coil you used as a the replacement part, if it is possible. I might like to try making one myself.

Thank you,
Dan

ddc5 the chainsaw works fine although it developed some carburetor problems that make it unreliable.
The particular part I used is Ignition Module Coil Fit Husqvarna 50 51 55 61 254 257 261 262 266 268 Chainsaw.
If you search for it in ebay you canfind one forless than 10$ free post.
I say go for it it is an easy transfer of a part.
Petros
 
Petros: I have that exact saw, still working fortunately. Would you mind giving a link to the vendor of the Husky coil?
Just in case I need to do a similar repair sometime
Mark
ps If I'm not mistaken the timing is set by breaker points so your repair would not change it

Mark Im sure it will be a piece of cake for you to make it fit if you ever need it. The problem with them parts is that they do not give any indication that they are about to fail! They fail exactly when you need the tool and you remain wondering "what the hell happened?"

Petros

John,
Thanks for your comments. Yes, if I was in business, it would be hard to justify the time spent-you could never make money on it. This design is really a pain since you need to totally disassemble it to do anything. The carb and coil are the last parts to be accessible. As far as this particular saw, I don't have much into it, it was basically free. It ran intermittently a few days ago, I made a few cuts with it with good power and then dead with no spark. So at this point, I have a pile of parts and it gets one shot to go back together, then scrap. I'll work on it between jobs on the IROC-(currently pulling the engine).
Incidentally, I agree about the electric tools. That will quickly become more mainstream as prices come down. Before my retirement, I was a hybrid / electric powertrain engineer for the last 15 years. What we can do now with variable frequency inverter drives, microprocessors and lithium batteries is quite amazing. The lithium cells are a great enabler, although still much less power density than gasoline. Small power tools can run with simpler control logic most of the time and are fast becoming a great alternative.

Dan

Guys,
I have a couple of electric ones also but the problem is that I cannot use them away from electricity grid.
Petrol-powered ones are convenient to use in remote areas.
Fixing it, apart from seen as a resurection project, it was a challenge that made me happy. I agree that if I had to do it for living I would not follow that route
Petros
 
ddc5 the chainsaw works fine although it developed some carburetor problems that make it unreliable.
The particular part I used is Ignition Module Coil Fit Husqvarna 50 51 55 61 254 257 261 262 266 268 Chainsaw.
If you search for it in ebay you canfind one forless than 10$ free post.
I say go for it it is an easy transfer of a part.
Petros
Petros,
Thanks very much.

Dan
 
Mark Im sure it will be a piece of cake for you to make it fit if you ever need it. The problem with them parts is that they do not give any indication that they are about to fail! They fail exactly when you need the tool and you remain wondering "what the hell happened?"

Petros



Guys,
I have a couple of electric ones also but the problem is that I cannot use them away from electricity grid.
Petrol-powered ones are convenient to use in remote areas.
Fixing it, apart from seen as a resurection project, it was a challenge that made me happy. I agree that if I had to do it for living I would not follow that route
Petros
Great work, Petros!
I've been scouring the web looking for a coil for Mini Mac 110 and Mini Mac 30 and have come away discouraged, thinking maybe this rabbit hole is going to get too deep for me (newbie). So I'm going to try your husq
20 years ago my father bought a McCulloch Eager Beaver II chainsaw to use it for branch cutting to the trees at a distance from home where electricity was unavailable.

View attachment 136012

He used the chainsaw the first season and had it in the store room for the next couple of years. When he tried to cut some thick branches three years later he could not start the engine. As the guarantee had already expired, instead of going to the dealer for repair he gave it to an “expert” friend of a friend to fix it. In the mean time he got ill and passed away within the next 6 months, so the chainsaw remained with the “expert”.

A year later my mother tried to find the chainsaw and the “expert” gave her an Eager Beaver II in a very poor condition, saying that it was beyond repair. I believe that chainsaw wasn’t my father’s chainsaw, but as there was no receipt I cannot prove anything. My mother stored it in a box and forgot about it.

Last week I found it consigned in my mother’s store room and took it to have a go with it.

I put some fresh gasoline, I pulled the rope several times, there is compression but no spark. When I researched for problems I discovered that the weak part of the chainsaws are coils that generate the spark.

The particular Eager Beaver II has a simple coil that is not working.

View attachment 136013

A search at ebay revealed that the particular coil is not available new anymore, it is hard to find and it is very expensive ($60 for a used coil).

I had to either forget all about fixing the saw or look for an alternative solution.

My first thought was to substitute it with another one from another maker. Unfortunately, every chainsaw maker designs his own coil! Some of them fit other models but none fits mine.

I noticed that coils consist of two separate parts: A laminate iron core and some windings encapsulated in a plastic container.

Most of the coils have similar containers but different laminated cores.

Solution is simple If I find a similar container I could change the core and have a brand new coil!!!!

I looked for a coil that has the same number of laminates with the original one.

It was easy to find it. Made for Husqvarna saws at a ridiculous cost (7.5$ including postage from Hong Kong!

View attachment 136014


I ordered it thinking that if it does not work I would have lost the equivalent cost of a six pack of beers!

Coil arrived and it looks promising.

View attachment 136015


I first removed the laminate core from the original part

View attachment 136016


Then, carefully, I removed the core from the new coil

View attachment 136017


A comparison of the two revealed that although they have the same number of laminates (i.e. the same thickness) they have minor differences to other dimensions so I must do some modifications to fit the old one to the new container.

View attachment 136018


First the part of the laminate that goes in the center of the container from 7.5mm had to be made 7mm. An easy work for my mill.

View attachment 136019


Next the container needed to be1mm thinner for the external leg of the laminate. Another easy job for the mill

View attachment 136020


Next, as the old laminate core is 1mm shorter, the container needed to be 1mm lower for a perfect fit.

View attachment 136021


Needless to say that During all this machining there was no wiring or electronics exposed so no harm done to the electronics.

So the old laminate iron core fits perfectly to the new coil

View attachment 136022


And there is my new part according to original specs (in comparison to the original)

View attachment 136023


It fits perfectly on the motor.

View attachment 136024


And, most important! it gives spark when I rotate the engine.

View attachment 136025


It remains to fix the carburetor and Its done!!!


Thanks for reading


Petros
Great work, Petros!
Love your Husq-hack coil. I've been scouring the web in search of coils for Mini Mac 30 and Mac 110 and have come up dry--not willing to pay huge for used ones that may not have a strong enough spark. So I'm hopeful that I can use your approach to solve at least one of the major problems with these saws. (Think the coil and config are similar). However, I still fear the dreaded "crank seal leakage," but I'll cross that bridge when and if I come to it.
Opah!
 
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