McCulloch SAW Engines?

[Harold Member]

Does anyone know of any web-sites or online articles on converting saw engines from the various manufacturers (Not necessarily just McCulloch) to either a Kart or Minibike application?

I have a McCulloch I-85 power-head sitting in the garage that I'd really like to do something with. I took a quick look at McBobs site & it looks like the I-85 has the correct crank in it.

While I'm at it... What is it that determines in which direction the crank revolves? CW? or CCW? Is it possible to reverse the direction of rotation?

Last but not least... Is there anything that can be done with those Mini Mac 6 engines? Aside from possibly mounting one in each corner for all wheel drive.

Thanks

[Mark Havery]

Harold,
In the October issue of the VKA's "Vintage kart Magazine" you will find the article on the conversion of a Clinton D65 saw engine into a kart engine. It is a tough 6hp 97cc engine, not at all like the A400-500 series. The D65 and it's brothers are the powerhead Clinton used for their E65 kart engines.
Mark

[david a luciani]

harold,
in about two weeks i'll be getting 11 more mcculloch chain saws and hopefully one root saw with a west bend in it.
if all goes well i'll post video of the breakdown of a saw to it's powerhead.
it's pretty easy.
this is an extremely short version but it should be of help to those who want to tinker and won't want to wait on me getting something online.
the first thing is to get your tools handy.
you'll need a flat screwdriver or two, a bunch of sockets, and a few wrenches and pullers.
you start by removing the bar.
then remove the front aluminum handle.
take all the screws out of the top of the gas tank. theres some that hide pretty good especially near the gas cap and back near the rear handle.
after all the screws are out gently pry the gas tank cover off.
if it doesn't pop off check for a missed screw, but sometimes you have to pry pretty hard.
with the top off remove the screw holding the felt thingy and take out.
theres two screws/bolts under there that need to be removed.
at this time you can also pull the carby as the bolts are easy to access.
save the carb, they're usually pretty good tilly's or flat backs.
remove the two lower bolts holding the carb manifold also take out the third one near the gas tank. take out manifold.
flip the saw on it's back.
remove the bolts holding the rear handle to the power head.
now the handle and lower gas tank should seperate from the powerhead. you have to kinda jigger the handle to get the gas bar clear. also be sure to cut the kill wire from the switch. be sure to leave as much as possible on the power head.
remove the four bolts holding in the oiler next. one of those bolts is a pain. i've got a ground down socket that fits to make bolt removal easier. most of the oilers will have a steel stuffer that also holds the oil in the oil tank. you need this part to keep stuff out of the motor so pop it off.Important put the saw over something that'll catch the old oil or you'll refresh the oil finish on your bench!!!
now it depends on which saw you have.
on all clutch removals you need to find the small hole in the fan cover thats used for pinning the flywheel. it's down near the powerhead on the back of the fan cover. put a small point , allen wrench, pick or whatever thru the hole and rotate the motor till you can push the pin a little father in . the motor shouldn't be able to rotate now. turn to the other side and remove the clutch nut.be careful some are left threads some are right.
at this point the bigger saws require alot more parts removed to pull the gearbox.
smaller saws require the clutch to be pulled.
use a clutch puller regardless. i ruined a crank being impatient by hammering the nut to loosen the clutch. take five minutes and build a puller if you don't have one. i used a scrap of angle iron , two screws that fit the threads in the clutch and an i bolt with a nut threaded on.i just drilled three holes one in the middle and two to fit the puller span on the clutch.
i put the big bolt thru the middle hole and thread the nut on .install the two puller screws and then tighten the middle nut so it lifts the angle iron away from the clutch. you may have to tap the middle rod a little to get the clutch to let go.
remove inner clutch and pop off the key.
take out the gear drum.
now you'll need to clean the motor of the years of goo.
depending on which motor you have you can then add a manifold and stuffer, mount it and run.
or with the step cranks you'll need to change the crank or fit up an adapter.
purists would put in a kart piston but we don't race so why bother?
best i can do with words
dave
btw i'm by no means an expert as i've only done a handful these engines . i'm just putting in my two cents in
D

[mcbob]

Thats a pretty good written description of how to get the unwanted bits off ya old Mac saw for Kart use now what we need to know is which Saw engines make the easiest conversions to the more popular Kart versions ......... Oh yeah this is a cheap way of messing around whilst your planning on extracting that last ounce of blood from these engines then you can bolt back on that mega dollar origional for the times that really count.

Mc Bob.

[david a luciani]

i wouldn't say the last drop of blood on a saw motor.from the 10 or 12 i've stripped back i've gotten way better parts than on some kart motors. it's not uncommon to get all usable bearing and crank parts that aren't very worn. many of these saws weren't put to alot of use while the kart motors were "ridden hard and put away wet!!!"

on the saws to kart id's :
well, there are some that will work alone.
a mc 1-60 becomes a mc6 when stripped.
at least i've been told. the mc61 might be the same i'll know more when the ones coming show up.
a mc 125 has the same or simular spec to a 101 except the head is fixed.
almost all the oldest saws have bolt on heads many have tapered cranks and connecting rods found in early kart motors. they all work on various kart motors.check mcbobs site for which ones for the removable heads and tapered cranks. on the connecting rods i think mcculloch only made about six different sizes. the parts number difference would indicate extra work like shot peening.btw any crank that hasn't got it's copper plating is indicative that it was shot peened as they did that after the cranks were plated.
there are parts that will make mc10's but you'll need two different saws to make one.i won't say which ones as i still need a few and the prices already run high. if you do a little cross checking and research the info is there to be found.
as you get into newer saws the heads become fixed so the aren't as easy to fake as a kart motor. the rings are bigger too(better cooling , slower rpm's). and many have a stepped crank which requires some fiddling to get a kart clutch on it.
that's not to say they won't work, they have the same cc's and potential but the aren't exactly a purist kart motor.Myself, i'd rather scatter a saw motor than a rare kart motor on a play day.
also prices being what they are i can build older motors for far less by saw scavaging.
as i've said there are other parts that are the same or speced the same.these saw parts go for big bucks as kart parts!!!same numbers just found in different places. if you really want to know check mcbobs site or get his cd and cross reference everything in it. i did.
also at the kart rally's there's always an old guy selling kart parts. most of the guys go buy whatever as cheap as possible and scoot. i prefer to stop and chat with these guys. ten minutes of chat can give me years of insight that was hard won by these fellows.at the big one this year i spent an hour or more talking to Steve who had alot of info and knowledge.i learned how mcculloch connecting rods were machined from coming in the door to finished rod. He'd even won a championship for Margay before retiring. Nobody but me took the time to talk to him??? strange to me as it's these guys that invented what we do.
anyway my finger is tired so my 2cents
dave

[Harold Member]

David,

Excellent info! Thank you very much. I figured it was basically remove as much saw away from the engine as possible. I didn't think it was as easy as your Write up though.

What are some of the possibilities on using/adapting self contained recoil starters.

I'm not building or re-storing a classic Kart. Being able to find a suitable saw & use that engine instead, holds more appeal to me.

Anyone want to take a shot at my direction of crankshaft rotation question or my, what to do with the Mini Mac 6 engine question?

Thanks

[Harold Member]

harold,
in about two weeks i'll be getting 11 more mcculloch chain saws and hopefully one root saw with a west bend in it.
if all goes well i'll post video of the breakdown of a saw to it's powerhead....

.....purists would put in a kart piston but we don't race so why bother?

dave
btw i'm by no means an expert as i've only done a handful these engines . i'm just putting in my two cents in
D

Dave, What are the differences in piston styles?

[Tom Smith]

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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

[Tom Smith]

Harold, I think the mini mac 6's have been adapted for use in radio controlled model boats and maybe motorized skateboards. Tom

[Harold Member]

Harold, I think the mini mac 6's have been adapted for use in radio controlled model boats and maybe motorized skateboards. Tom

I was thinking they might be a good engine for the RC world.

As far as skateboards... I woulda 'bout died & gone to heaven if I could've found one of these engines when I was a kid. I wanted to build a motorized skateboard so bad.

Speakin' 'bout heaven & what not... That pic you posted above. Is that a book shelf in your Study or an Altar? Very nice!!!

I saved that pic, to show to the little woman next time she asks, "Are you sure you need another engine?"