McCulloch Super Pro 125 chainsaw
with Kart 101B motor
As you can see McCulloch's SP125 was an easy host to the Famous
Mc 101B Kart Engine offically sanctioned and offered by the McCulloch factory to suit the bigger timbers of the Pacific Northwest of America ............. this made an already impressive saw even more powerful and again bigger and tougher competition to other saw manufacturers of the mid to late 1970's
.

Note the larger capacity muffler and the recessed bolts to retain the muffler.
This muffler i'm sure is off the Mac 895c of 1972
.
Mc - Kart engined McCulloch SP125
Super Chainsaw of the Forest.
The Ultimate factory Option
Note this saw is not mine but was auctioned on Ebay
SP125 carb with  the adjustable high speed mixture screw.
Another view of the special muffler as the 101b Kart engine had a recessed exhaust mount between the cooling fins and the SP125's had a raised exhaust boss and larger studs retaining the muffler.

The muffler shown fitted is off a McCulloch 895c
.
Looks like standard Kart ignition the SP125 used a different coil mount and coil.
Many thanks to the Ebay seller Sawking for adding these extra pic's to his Ebay ad.