rearenginekarts.com

some companies had 2 strokes that rotated either way. it's a timing matter because in theory any two stroke is capable of running either way.. the macs rotated in one direction as far as i know.

the mini mac is a good limbing saw and general small cuts. it really likes this job and should continue on that path.

the difference in the pistons in macs is: chainsaw big wide rings except some super saws and kart motors narrow thin rings except some of the oldest models.
this has to do with reducing drag . you sacrifice cooling by using thinner rings to allow the piston to move faster rpm's. good for karts bad for chainsaws.
there are different pistons as they get younger but that reflects the changes in block styles.
Aaaaand as always putting in the correct part is the path of least resistance.
dave
btw if you want to sell that 1-85 i might be interested.
send a p.m.
D

Tom Smith wrote:

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Mc Bob, Mcculloch built a saw with a slightly modified version of the first 101s, the 797/Super 797 series. I'm of the opinion it's the best 125cc reed valve saw they built. It's the only Mcculloch saw that I know of that has the large single booster port and the bridged exhaust port. My three favorite Mccullochs I have are two beautiful roller nose Super 797's and an almost new Super Pro 125 that I like to just look at and start once in awhile. Those 3 saws made me a believer in the benefit of compression releases for starting the bastards!
Be careful with collecting old Mccullochs and thinking like I did that I needed to have 3 sets of spare motors for my 3 engine Max-Torque Kart and then ended up with about 20 of the things!
BTW the two motors on the floor are a matched set of never run Super Pro 135's

Nice collection of Mac's Tom i envy you especially those two Mac's sitting at the bottom of the pic and if you ever happen to stub ya toe on either one of them then you could package them as a pair and send them downunder to me .... i promise to luv and honour them ......
How about sending this old fella a couple of nice pic's of these Mac 135 cutties ..........

Mc Bob.

david a luciani wrote: ....btw if you want to sell that 1-85 i might be interested..... send a p.m. D

Dave, I sure appreciate the information & the interest in the I-85 power head. I actually have plans for that guy & was thinking about possibly disassembling the saw, clean it up & convert if for use on a minibike. All the while I would take a few key pics along the way & post them up.