Mc 20 clutch removal

[Dave Neis]

I'm new here and am restoring a 1962 mac go cart with a mc 20 motor. The clutch does not have a hex nut but it a circle with qtr moons cut out. Is there a special tool or do I have to make one. Also is it rt hand thread. I also need a flywheel and some rebuild parts any ideas where to go? Thanks fo the help Dave

[Rob Voska]

RH threads. Use a flywheel wrench or there is a notch in the back of the flywheel you can put a bolt thru to lock crank so you can get clutch off. Need picture to understand the 1/2 moons but I'm guessing it's a Noram clutch & the nut might already be gone. Don't get in a hurry & ruin something. Post a picture & we will help you figure it out.

[ted johnson]

This is going to sound silly, but might it possibly have an oil clutch? Are there small screws in the 1/4 moons? If so, remove those screws and the cover they hold on. The clutch nut may be under that cover if it IS an oil unit. Do it over a drain pan! The flywheel is an ordinary Mac unit. Find one here on the forum, or go to eBay. A five degree flywheel is O.K. to use. TJ

[steve miller]

hey guys i was thinkin dont some clutches on mccullochs come off hard because of the taper ..?? ive had some that are kinda tuff gettin off .. even after nut is removed ..

[david a luciani]

steve,
most clutches have some sort of tool to remove them.
i've found the best approach is to use the tool rather than the ole give it a good rap.
alot less broken parts that way.
the taper can really grab a clutch especially if it's been run real hard.

dave,
there are some nuts made with little indents instead of traditinal hexes.
they are found on alot of tamper resistant bathroom fixtures.
that being said it's unlikely that one is one the motor.
post a pix so we can give solid advise.
if you can't figure out how to post ask and we'll help you or post the pix for you.
dave

[steve miller]

Dave ..i no its the best thing in the world ...yrs ago i made a tool that kinda looks like a ball joint pickle fork its got slot 1/2" , 9/16", 5/8", and 3/4" stepped in it ..so far its worked very very good ..no possible way to ruin bearings seals or anything by exessive pulling ..cuz your always prying against crank collar ..it works for me ..i cant seem to keep track of 5 different pullers .. but that thing and a hammer is always in my box ..Lol..

[Jeff Campbell]

Dave,
Does that clutch look like any of these?


We need to understand what you have to help you. FYI - the Mac kart engine cranks all have a tapered clutch shaft, with a threaded end (all early motors had RH threads). The clutch locks on that taper, even with the clutch nut off, the clutch hub will remained locked on the shaft. A puller is required for getting the hub off the shaft once the nut is removed. On some clutches a 3 jaw puller will work if you can firmly lock on the hub or drum (on inboard clutches). On other clutches they are designed for the use of special puller tools, some can be made easily, others can not. If you can figure out what you have, then we can tell you what tool to use.

Like others have said, I don't recommend the old school method of wacking a knockoff nut with a hammer to pop off the clutch ... that's a risky deal and from my experience it only gets it off a fraction of the time.

Jeff

[Rob Voska]

I got him taken care of for now. Someone put a LH thread crank in a MC 20....

[Scott Kneisel]

Yeah,
The later replacement crank for the Mc20-45 has a LH thread and no keyway. Hard to tell what you got though if you didn't install it yourself.

[Rob Voska]

Thanks Scott. I learn something new every day! I didn't know that.