McCulloch CP 125 build

[bryanr2]

Subbed

 

[Chainsaw Jim]

Here's a close up of the weep hole that was mentioned.
Thank you Mark and Lee for your information about that. I was actually curious what its purpose was for. I did have a theory that it might be for greasing between them. lol

 

[smokey7]

What are the differences between the sp 125 and the cp 125?

 

[backhoelover]

@Armbru84 sent this beast my way to get a little tlc.
I'll be giving it a thorough, and replacing all maintenance items. There's also talk of having a little bit of port work done to it.

View attachment 106679 View attachment 106680 View attachment 106681 View attachment 106682

I'll be doing this teardown and build in real time so please be patient.

 

[Lee H]

What are the differences between the sp 125 and the cp 125?

You ready

CP125 has different lower forward AV mount, Three leg coil, different wiring
for stop switch, 797 style decomp, different porting, No throttle lock, Air
filter cover has a rear opening, Round directional muffler, Narrow fan housing.

Early SP125, Has 2 leg coil, updated lower forward AV mount, Wide fan housing,
Push type decomp, Updated stop switch wiring with upper front AV mount ground
strap, Rectangle muffler with muffler guard, Different porting, No rear opening
in air filter cover.

Late SP125C is same as early except for Chrome bore, Fixed HI jet in carb and very
late ones have chain brake.

 

[Chainsaw Jim]

You ready

CP125 has different lower forward AV mount, Three leg coil, different wiring
for stop switch, 797 style decomp, different porting, No throttle lock, Air
filter cover has a rear opening, Round directional muffler, Narrow fan housing.

Early SP125, Has 2 leg coil, updated lower forward AV mount, Wide fan housing,
Push type decomp, Updated stop switch wiring with upper front AV mount ground
strap, Rectangle muffler with muffler guard, Different porting, No rear opening
in air filter cover.

Late SP125C is same as early except for Chrome bore, Fixed HI jet in carb and very
late ones have chain brake.

Which came first, the SP125 or the 101b?

 

[Hinerman]

Which came first, the SP125 or the 101b?

the SP125 according to the internet

http://www.acresinternet.com/cscc.n...cc6e27f21cad04bb88256c2e00782d34?OpenDocument

https://en.wikipedia.org/wiki/McCulloch_MAC-101

 

[Al Smith]

I'm going to tell you the search for a good 101 is like like finding a needle in a hay stack .At least for a reasonable amount of money .My buddy Louie who I went to apprenticeship with and is one day older than me has searched .He was number 2 nationwide in the kart circuit two years in a row and ran 101's and still has his porting notes .At one time just about everybody sold components for these ,Wiseco Horstman etc .Try and find them now .Although it's a small number looking for same those who have them know what they are worth .I'll find one eventually probably when I least expect it .
If and when I find one I'm not going to stuff it into a 125 but rather some other lesser expensive chassis .The 125's will stay the way they are .A hotty is a hotty not something you cut firewood with .

 

[bryanr2]

You ready

CP125 has different lower forward AV mount, Three leg coil, different wiring
for stop switch, 797 style decomp, different porting, No throttle lock, Air
filter cover has a rear opening, Round directional muffler, Narrow fan housing.

Early SP125, Has 2 leg coil, updated lower forward AV mount, Wide fan housing,
Push type decomp, Updated stop switch wiring with upper front AV mount ground
strap, Rectangle muffler with muffler guard, Different porting, No rear opening
in air filter cover.

Late SP125C is same as early except for Chrome bore, Fixed HI jet in carb and very
late ones have chain brake.

So which is the one to have?

 

[Lee H]

Kind of a opinionated question. Apples to apples they are very close in performance.
I like the SP125's updates over the CP but I like the CP air filter cover but in a production
world that filter cover got plugged up quicker. I still prefer a 797 over any CP or SP. I like
the old school non av design but then again I don't run them all day everyday.
Any good running 123cc Mac will put a smile on any ones face if they know how to run it.

 

[Al Smith]

Having tried it a time or two running a big Mac for a long period of time is not the most pleasant experience in running a chainsaw .Try it with a 48 inch bar sometime .It won't run out of power but you will .Think about those PNW loggers at about 165-180 pounds who did that for days on end .My goodness they could burn 3000 calories a day and never gain an ounce.Tough old birds

 

[p61 western]

So which is the one to have?

One of each lol.

 

[Chainsaw Jim]

If and when I find one I'm not going to stuff it into a 125 but rather some other lesser expensive chassis.

I'm trying to talk myself into dumping a cp125 engine into this thing..

According to specs it's 5 pounds lighter than the 125 saws.

 

[Lee H]

That would be a task as the super 250 is not a super series motor. A Mac 91, 92, or 93
would go in and make a nice 100cc hot rod.

 

[Chainsaw Jim]

That would be a task as the super 250 is not a super series motor.

Is it because of the flywheel and recoil?

 

[Chainsaw Jim]

Any plans for reed upgrade?

Actually I may not have a choice because the reed petal is broken.


There are no direct replacements available anywhere local or online. So I'll have to use a petal from something else and cut it to match.

 

[T.Roller]

One of each lol.

Best answer

 

[Lee H]

Is it because of the flywheel and recoil?

Cylinder cover which is all part of the left motor case where the points
reside as well as the recoil fan housing.

 

[Lee H]

Put a SP125 intake on it as they have the two reed pedal set up
like what was used in many older saws like 795, 797, etc. The
CP is the only saw I know of that tried that stupid big single reed.

 

[Sleeper]

Actually I may not have a choice because the reed petal is broken.
[snip]

There are no direct replacements available anywhere local or online. So I'll have to use a petal from something else and cut it to match.

Like Sir Lee H said... SP125 intake... go back to the old school two petal...


or if the customer really, really wants it, fit a kart intake...