Building a 101b.

[burl1984]

I have been building a vintage 101b for a few months now and had tons of trouble with the OEM BDC14 carburetors.

I posted a bunch on this thread.
http://www.arboristsite.com/community/threads/mcculloch-carburetors.122113/page-7#post-4809797

Here is a current modification that I have done. It'a a Mikuni SBN 38mm jetski carburetor adapted with a homemade adapter. I was given the advice to use this carburetor over the oem bdc carburtetors by Fireball Racing in central CA.



Let me know what you think, I'm hoping to be a little more competitive with this saw than I have been with my 3120xp.

 

[spencerpaving]

Nice!....let's see it in some wood!

 

[burl1984]

I still need to mount the fuel tank better before I run it too much more. The plan is also to fab up an air filter mount as well and run a green weenie filter. I'm planning on running it at the North Fork Lumberjack show on July 6th. Hopefully i can get a couple of test runs in first. There will be a few SP125's and 101b's at this show as well. I'll see if I can get videos of all the cuts to compare mine.

 

[Pinechunker]

Last years winner was 13 seconds in 40" wood

 

[sawfun]

I have a BDC on mine and have no issues so maybe I'm lucky. I had to find a needle spring that was stiff enough to not allow flooding. Also I run the lever .010 below the gasket surface also run a full 1/4" fuel line so no restrictions.

 

[Tenderfoot]

If you can fabricate a mount, a Napa 6637 air filter would be both hilariously large and highly effective. The thing is about the size of a small child's torso. The outlet on it is 4 inches. Adequate for some 450 hp 6-8 liter diesels.

 

[trappermike]

I think a 34mm carb is the r1ght one,I think a 38 is too big,will generally lose most power except a few moments. Try a 34 and compare with actual tests.

 

[trappermike]

OH,I used to know Bob Walker well,he said any good McCulloch mechanic had pits in their forehead from needle bearings flying out! I kid you not! I do know another guy who built them,he used main bearings that were all balls,no cages,I found out they are called "Full compliment bearings" There's something for you guys to get hot for!

 

[trappermike]

One of my secrets gone...

 

[trappermike]

Don't worry I already checked,they don't make them in the small 6202 or other common sizes for us.
sizes,,,

 

[sawfun]

OH,I used to know Bob Walker well,he said any good McCulloch mechanic had pits in their forehead from needle bearings flying out! I kid you not! I do know another guy who built them,he used main bearings that were all balls,no cages,I found out they are called "Full compliment bearings" There's something for you guys to get hot for!

Yup, when I pressed mine off, the whole thing fell apart. Maybe we should call it a buckshot bottom end? if I ever do run nitro the power head is getting wrapped in Kevlar. I still have some from my drag race days.

 

[trappermike]

Well look for the "full compliment bearings,and send us some photos of needle bearing poc marks,hah hah
Sorry to tell you my 090 in the 80's beat the McCullochs clean every time! It was the first time a chainsaw could beat a McCulloch gokart engine!

 

[sawfun]

It's damn hard to beat 137cc's with 123. I may have to try my 090 against my 101 with 72" bars and see who wins. I pretty much know already.

 

[trappermike]

You have to do very extensive work to an 090 to beat a 101