rearenginekarts.com

hi all, i just got what was supposed to be a mac 8 motor off ebay. i mostly bought the package to get the motor mount that was on the motor. upon arrival i inspected my barn fresh purchase. i clicked onto it not being a mac 8 right away. on inspection i noticed a short coil brace that seemed to be floating. then i noticed that the cover was shimmed out with washers to make it fit. then, stupid me i checked the numbers again. this time i used macbob's very cool site to check the numbers.it seems i have a S44A chainsaw motor.i checked the stroke and specs and it seems to match the stock mcc10 specs.
i have another motor i think is a mcc 10 .i posted pix its the sorta blue one with gopower parts. am i right about that being a 10?
anyway , except for the heads and the missing oiler nub these motors look pretty much the same block wise. would i be able to run them as a pair? it would be neat to put them on the gilson as i believe that's what it came with . any comments? thanx dave
p.s. below are pix

G'day David,

Thanks for your kind words on my web site but a word of caution at this stage all might not be gospel as regards my entries now if anyone spots something wrong then i can correct any mistakes but i hope at the end of the day it helps in getting info from one spot and not have to wander all over the net looking for it if it's there at all.

At your service Mc Bob.

now i've really gotten confused. it occured to me that the cover from a 90 wouldn't work with a shorter crank . i checked and the crank is the longer style. as i understand it the 100 series motors all had short cranks. but the only kart motor in the 90 series with ball bearings on both sides i could find in the specs was the 92/93. that doesn't seem right . any ideas short of a complete teardown?

David,

As soon as you get this figured out please post them or let me know. I'd like to get more information on mc10's and early super series motors. I get a lot of questions on them lately but just don't remember enough about them and don't have pictures like I have for the later 101's. Good Luck

David,

The ignition side of the Mac cranks come in two lengths... the longer version fits with the 6,7,8,9,90,91,92,93,49 model motors and the shorter versions fit the "super series" engines such as the 20,30,40,45, 70,75,100,101s
The shorter cranks cause the flywheel to sit closer to the centerline of the motor so the coil must also sit closer thus the coil posts will be shorter on those blocks.
Only the 92 and 93 cranks were designed with the long ignition side and journals for ball bearings on both sides.
Hope this helps.
Steve O'Hara

Mc-10s have MC-10 stamped where the machined off oiler boss was. Late Mc-10 crankcases have material added around the pto bearing pocket to provide clearence internally for a machined relief so a larger (crankshaft P/N 55517) counterweight will fit. The early Mc-10s did not have the additional thickness on the crankshaft PTO counterweight (crankshaft P/N 55257) Late crankshafts will not fit early crankcases so says Mcculloch kart engine bulletin K108 dated 12/16/60.
A third Mc-10 crankshaft (P/N 48696) has the heavypto side counterweight and .035" deep grooves machined in both counterweights which identifies it as a 1.625" stroke crank for a Super Mc-10.

examples of the 3 different cranks used in Mc-10 kart motors. PTO bearing OD is same as Mc-92/93 and Mc-101

Thanks Tom and Steve,

I 've recorded all your text and details on mac10s and hope to get it in my website soon so we can all reference it in the future. Anything else you want to spill-out on this thread? Please go ahead.

Thanks Tom, Thats the kind of info we are always looking for. Ron

Hope you fellas don't mind but i added these details to my Mac site this morning my time now i keep a close eye on all aspects of our dear Macs for future reference.

http://www.macbobaust.com

Mc Bob.