# Mcculloch Chainsaw Eager Beaver Ii Ignition Coil



## petcnc

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.




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.




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!





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.





I first removed the laminate core from the original part





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





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.





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.





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





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





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





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





It fits perfectly on the motor.





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





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


Thanks for reading


Petros


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## JimDawson

Nice save!


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## petcnc

JimDawson said:


> Nice save!



Thanks Jim!


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## Ulma Doctor

very nice work!


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## FOMOGO

Nice job. Parts is parts. Sometimes you just have to teach them to get along. Mike


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## petcnc

Ulma Doctor said:


> very nice work!



Thank you Mike


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## petcnc

FOMOGO said:


> Nice job. Parts is parts. Sometimes you just have to teach them to get along. Mike



Mike I like the way you put it:

"Teach the parts to get along"

He he he


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## rgray

Love it. I've seen some interesting things done to save coils but never to this extent.
One thing to think of is the ignition timing. Hopefully it is close enough.
Diameter of the flywheel and stroke of the engine differences can put that timing in the wrong place possibly.
Those little eager beavers were  a bit of an aggravating thing to keep tuned and running new. If lucky you may have just
made the best running beaver yet.


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## Bill W.

I think that while fixing this chainsaw you had someone very special looking over your shoulder. 
That provides enough inspiration to overcome most any situation.  Nice job...  Bill


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## petcnc

rgray said:


> Love it. I've seen some interesting things done to save coils but never to this extent.
> One thing to think of is the ignition timing. Hopefully it is close enough.
> Diameter of the flywheel and stroke of the engine differences can put that timing in the wrong place possibly.
> Those little eager beavers were  a bit of an aggravating thing to keep tuned and running new. If lucky you may have just
> made the best running beaver yet.



Well rgray I considered that. As the timing depends on the position of the core "legs" relative to the magnets of the flywheel that's why i kept the original laminate core. I just made one of the legs 0.5 mm thinner. I suspect it might affect the timing but I dont know to what extent. I will test it and inform of the results.
Petros


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## petcnc

Bill W. said:


> I think that while fixing this chainsaw you had someone very special looking over your shoulder.
> That provides enough inspiration to overcome most any situation.  Nice job...  Bill



Bill I must admit it was a loooooong shot to find a coil that with minor mods did the job.
I think my father would feel less guilty now and would be very proud of his son...
Petros


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## thomas s

Nice job Petros.


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## petcnc

thomas s said:


> Nice job Petros.


Thank you.


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## ddc5

petcnc said:


> 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


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


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## matthewsx

This thread demonstrates why I scrapped out so many of these and other small engine powered tools when I ran my repair business. I would often have to explain to customers why I couldn't fix their tool for less than it cost to purchase a new one, and why doing so wouldn't be ethical for my business.

So, if you (ddc5) want to embark on this repair I believe you now have information to start with. Hopefully you already have a vertical mill and whatever other equipment you will need to do the job. I can say without hesitation that picking up a replacement tool (new or working used) will definitely be quicker and/or cost less than doing the repair illustrated above.

I did occasionally have customers like the OP for whom the tool in question was a physical link with a lost relative and for whom repairing the tool, outboard motor, ice auger, etc. was more about that connection than having the item to do a particular job. For those customers I was always willing to provide advice and parts but I had to tell them that doing the repair was "their project'.

Cheers,

John


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## ddc5

Oh, I understand your point, it is  cost / benefit tradeoff.  I most certainly can buy a new saw if necessary.  It just always bothers me to throw away perfectly good mechanical devices because some relatively small part is no longer made.  And, as manufacturers integrate mechanical with solid state, it gets even more difficult.  I appreciate the innovative solution here and it looks like something that I can do with tools I have access to. Many times the old pieces of equipment are worth saving because they actually are more rugged than the cost / weight reduced new tools.   For perspective, I say that as a recently retired automotive engineer with a little more time to do these things.  In some of my increased available time, I have some old car restoration projects. Currently, I have a 1985 Camaro IROC-Z "barn find" that has been parked for over 25 years.  There is much satisfaction for me in putting these things back together again and making them run.


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## markba633csi

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


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## rgray

markba633csi said:


> ps If I'm not mistaken the timing is set by breaker points so your repair would not change it



No points in these it's an electronic ignition. Timing depends on the coils position to the flywheel magnets.
Small timing change avalable by increasing/decreasing the gap to the flywheel.


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## matthewsx

ddc5 said:


> Oh, I understand your point, it is  cost / benefit tradeoff.  I most certainly can buy a new saw if necessary.  It just always bothers me to throw away perfectly good mechanical devices because some relatively small part is no longer made.  And, as manufacturers integrate mechanical with solid state, it gets even more difficult.  I appreciate the innovative solution here and it looks like something that I can do with tools I have access to. Many times the old pieces of equipment are worth saving because they actually are more rugged than the cost / weight reduced new tools.   For perspective, I say that as a recently retired automotive engineer with a little more time to do these things.  In some of my increased available time, I have some old car restoration projects. Currently, I have a 1985 Camaro IROC-Z "barn find" that has been parked for over 25 years.  There is much satisfaction for me in putting these things back together again and making them run.


I get what you're saying, and the sentiment behind it. If you have the time to put into this saw, and wouldn't rather be working on the IROC then go for it. Just realize you're not talking about a Sthil here or even an older Mac, these were throw away saws when they were built. 

My experience comes from working on at least a dozen identical units. My process was simple, check for spark, check compression, check for running with starting fluid. If it failed any one of those tests it would get yellow tagged and the customer notified. I had to be ruthless like that since people would bring me stuff like this all summer long and expect to get a "practically brand new" good running item for $20 and a handshake. I couldn't waste my technicians time on things that weren't worth the cost to fix them, margins were already too tight.

That's where the "your project" part came in. I know guys like to tinker and it's not up to me to tell anyone what's worthwhile and what isn't. I was in business back then and being in a small town I thought it better to send work away rather than tick off my customers with a bill that was more than the tool was worth. 

BTW, I've been switching my gardening gear over to battery powered for the past few years and I've never been happier.


Cheers,

John


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## matthewsx

Oh, one other thing to look out for on two-strokes. You can have a brand new carb, working ignition and plenty of compression and still not be running. That's because two-strokes rely on having a good seal at the crankcase to draw a fresh charge into the engine through the carb. If either side crank seal is leaking it won't ever run, or run right. To test for this you have to block off the intake and exhaust and pressure test the whole unit, also something that's more work than most small pieces of equipment warrant. 

Cheers,

John


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## ddc5

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


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## john.k

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.


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## matthewsx

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


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## john.k

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.


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## petcnc

ddc5 said:


> 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


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## petcnc

markba633csi said:


> 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



ddc5 said:


> 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


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## markba633csi

Thanks Petros I found it:








						Ignition Coil Module Magneto Fit Husqvarna 50 51 55 61 254 257 261  Chainsaw   | eBay
					

Find many great new & used options and get the best deals for Ignition Coil Module Magneto Fit Husqvarna 50 51 55 61 254 257 261  Chainsaw  at the best online prices at eBay! Free shipping for many products!



					www.ebay.com


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## ddc5

petcnc said:


> 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


----------



## kempd

petcnc said:


> 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


petcnc said:


> 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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