OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Chainsaws and Concrete Cutters McCulloch Chainsaws Mac Super 250

Speedy, you said you had a weak spark with the points, is it any better with the module fitted? You need to be able to see the spark through the spark plug held against the head to get an idea if the spark is good enough

The spark is weaker with module, but still just see it with points.
I want a big blue spark like many B & S engines I have worked on. I have a few BS coils. Might try to put one on....
I'll measure the holes on the Mac coil.
cheers
speedy

Don't attempt it speedy it won't work, you can't get the timing correct, don't ask me how I know. It sounds like your coil is the problem and that will probably be the end of the chain saw. I have a Solo chain saw here with a dead coil, just haven't got around to taking it to the scrap and it is in good condition apart from the coil. I also has an Echo blower with a dead coil that I tried to fix for a friend, just on $100 for a coil so it to went too the scrap.

If you are using resistor plugs that spark will appear weaker. If using a resistor plug try a non resistor type.

Also the color will not always be bright blue. If you live near the sea coast it can even be orange due to sodium in the air. Here the sparks are usually white.

Thanks AVB, when I use a non resister plug, people around the neighbourhood have problems with their TVs ............
The guys down the road have an old motorbike and when I hear it start the TV goes haywire......
It did fire for a blast once..... that's why I keep going.
Is there a way to test the coil? My mate will but another coil as he wants to get this old thing setup as a log slab cutter. He will make a steel frame up and make slabs. They use them for fencing... and other things.

thanks
speedy

Speedy which coil do you have? Or would you rather have the 1963 service manual and the 1965 supplement?

It's a 1970 model saw, with a yellowcoil. I will get the number.
speedy

See if this helps then.

AVB, It has E67 stamped on coil,so it's top row.
Just bought a cheap multimeter, so now I will do some measurements.............. bit of a learning curve/hurdle.
speedy

OK AVB I did some testing and familiarising with multimeter.
Got reading of .02 on primary , should be .025 to .5, but then it was all over the shop... changing........
But the secondary was more stable at 5.89, should be 3.5 to 5.00

I will look around for another coil...... they are laying around sheds etc , just a matter of finding one.....
speedy

I heated up the coil in case there was moisture in it, closed the air gap flywheel, bodgee rigged a Victa condensor.
Bingo, a big blue spark.
I heard there was only one Macullock condensor so if I can't get one, I'll just use a Victa one.....
Feels better
speedy

It should be .18 - .22 uF capacitor.

Cross referencing here of the Mac 50074 (superseded to M85358) is coming up with a Kohler pn 230722S

OK, I got the Kohler condensor, and fitted it, great spark, bit white not blue, but that was OK.
I assembled it and pulled away a bit, it fired a couple of times, but dry plug so no fuel.
I pulled carb apart and put correct gaskets in in right order, but with sore arm, I mounted the saw in my vice and used electric drill to turn it over...... it fired once.....
But a wet plug......... even used starter spray.......................
One of my new year resolutions is to get this Super Mac out of my workshop..............!!!

Yesterday a bee was inspecting all the holes in it looking for a new home.........a big gray bee. Wouldn't leave me alone....
Maybe it was the colour yellow..... want to hear something funny.
I was at the pool with a ladyfriend once and she had a t shirt on with a big sunflower pic on it,,,, and a bee landed on the flower......
speedy

Speedy I worked with a bloke with a big mop of red hair, he was always being chased by European wasps, bees never worried him it was always the wasps. He would start swinging his arms around and I knew he wasn't having a fit, wasps were after him. I did tell him to dye his hair black.

I put 4 Orings on machine today, 2 in carb and 2 for fuel and oil caps....
Didn't fire, pulled the spark out, one flash then nothing.
I need a coil.........
There must be some laying around.........
I'll check US forums
Even out Mac dealer... he didn't have anything come up for that model, but I will try another dealer..
speedy

Speedy you don't give up easily, can't say I have that determination

The spark was bad, I replaced the two wires and clips on the coil and now I have BIG spark...
It starts and runs with carby starter...... so points and coil are good now....
I put a kit in the Tillotson HL 63G carby, but I must have missed something.
I see on youtube some excellant videos on installing the kit and learning about this fantastic carb... so many models....
Even new Chinese copies for $16 or $20...... so prospects are looking up.
work to do
speedy