Mcculloch sp125/101b kart saw build thread

[Bigmac]

Sounds pretty good, What WB carb did you end up using.

This is the wb3, but you need to swap out the fuel barb to a 90°. Have thought about using the wb37 it already has the right fuel barb and is a little larger

 

[Bigmac]

And the his is the air filter after 4 cuts!

 

[Steve]

And the his is the air filter after 4 cuts!View attachment 238045

Air injection was definitely the best thing to happen to chainsaws!

 

[Bigmac]

Air injection was definitely the best thing to happen to chainsaws!

That’s true, would be nice if other manufacturers would have come on board earlier, but these are way before that! Lol

 

[Lee H]

What size bore is the WB3, I have a WB20 with a 28mm bore. Thinking of trying
it on my unfinished 101 project that i tried a HL360 and runs like chit.

 

[Bigmac]

What size bore is the WB3, I have a WB20 with a 28mm bore. Thinking of trying
it on my unfinished 101 project that i tried a HL360 and runs like chit.

The wb3 is 25mm bore, do you have a pic of the wb20?

 

[Lee H]

Here you go. Only thing i would have to do is change the fuel pump cover
for one with the external pulse line.

 

[Bigmac]

Here you go. Only thing i would have to do is change the fuel pump cover
for one with the external pulse line.

View attachment 238149 View attachment 238150 View attachment 238151 View attachment 238152

Nice, That’s a big one! My intake boot is limited to a little over an inch 1.060, so I think the wb37 is the biggest my boot will take, and the configuration would work well. The wb3 is off the Yamaha 100 kart motor and the wb37 is off up to 200cc paramotors,was looking up the spec on those motors and they make 30hp with the wb37! I think I might try one, it will be an easy swap at this point. Am really happy with the wb3 thou, it’s super responsive.

 

[Lee H]

What's the bore on the WB37

 

[Bigmac]

What's the bore on the WB37

I think it’s 27mm, but I can’t find that info right now,
Terry recommended the wb3, he said it was a decent kart carb, the Yamaha 100cc kart engine makes 18.5 hp with it totally stock

 

[Bigmac]

Swapped the saw over to .404 8 pin, and a 50” general bar along with a nos clutch. Hopefully get some time to test soon

 

[Bigmac]

Got my Oiler situation figured out, I was careless and had the wrong bar plates, and must have also been slightly plugged up, it’s now oiling like crazy!!


Bought a 797 parts lot, so I was able to get a stuffer, going to test the .404 Chain first, and then swap in the 797-101 style stuffer at some point.

 

[Lee H]

What stuffer you got in it now?

 

[Bigmac]

What stuffer you got in it now?

Standard 125, the smaller one

 

[Lee H]

125 is the same as a 797, You can massage a 790 or 795 to fit and act like
a racing stuffer as it fills more of the crank case.

 

[jacob j.]

Standard 125, the smaller one

125 is the same as a 797, You can massage a 790 or 795 to fit and act like
a racing stuffer as it fills more of the crank case.

My dad ran an Mc-20 kart stuffer in his one kartsaw and did some work to it with filler and grinding. I'll get pictures of it later today.

It was in the 101b kartsaw that was his favorite of all time (.020" over, running the Pro Mac 650 ignition and HS-70 carb).

 

[Bigmac]

I thought the 797 and 101 stuffers were the same volume wise, and the 125 was smaller.

 

[jacob j.]

I thought the 797 and 101 stuffers were the same volume wise, and the 125 was smaller.

I'll look today and see if I can confirm - I just pulled a 797 Super down this week that had never been apart.

 

[Bigmac]

I'll look today and see if I can confirm - I just pulled a 797 Super down this week that had never been apart.

That would be great. Maybe my stuffer is of a 795, it has the same profile as a kart stuffer I have aroundJust no Oiler holes.
I don’t have any ipl’s for the 797 and 797 super, but the cp 125 and sp125 have different part numbers for there stuffers, not sure if there are any differences thou.

 

[Lee H]

I thought all the 123cc Mac's were the same configuration where it goes in the block. The 101 stuffers
are missing the oil holes for the manual pump and auto pump. The 101 also has a reinforcement that
needs to be milled off so the oil tank can go on.