Building a SP125C / 101B Kart Saw

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Funny about that side cover gasket. It's a dead-nuts fit as a head gasket.

There's a reason for that...

You can't use an "O" ring where the #62 gasket is on any 123cc Mac
do to the cut out in the block. All of the 123cc Mac's i have had appart
were sealed with some type of sealing compound. You can use a gasket
but i haven't seen a gasket yet in all the 123cc Mac's yet. Funny how the
101 IPL shows a gasket but the 797, CP125, SP125 show nothing.
I will continue to install the seals the way i have always seen them.


Lee

I've been using the old-school grey Dirko sealer. No O-rings or gaskets.

The O-rings work on the early kart engines with the flat mating surface.
 
How is the "O" ring going to seal where the
cut out is for the crank install. It won't.




Lee

Well you do your thing and i'll do mine Okkie Dokie

McBob.

sp125cyl.jpg
 
Last edited:
You're referring to the cut out to clear the rod journal off the crank, correct? No way an o-ring would do anything to seal the side cover.

That is correct Brad, Thats why all of the
123cc Mcculloch IPL's show no "O" ring.
Mcculloch used some sort of sealing stuff
to seal the case. Which also sealed the 3
open screw holes to prevent any leakage.
The 101 IPL is the only one to show a gasket.
But all the 101's i have had appart have had
sealer and no gasket.



Lee
 
Every 125 I've pulled apart had some kind of sealer. All of my dad's saws were sealed back in the '70's when he rebuilt them
with the old-school Yamabond (in addition to being a McCulloch nut, he was a Yamaha guy.) I believe in those days the
Yamabond was light blue. No gaskets or O-rings. On the saws that he had switched to the solid-state ignition, he'd only
installed one seal per side. These were saws he ran for years in big timber with long bars and they did fine that way.

He still had three saws though with points- two 797s and a CP-125. Those all had the original configuration as far as
seals go.
 
Well debating to use an O'ring or not is not my arguement here, it's what i use .... you do what you want its your choice.
and it works for me regardless of what you think.

After seeing great blobs of silastic and god know what else used to seal this joint and seeing the excess dribbling everywhere inside the engine i'll stay with the o"ring.

McBob.
 
Last edited:
Bob, when you mounted the carb did you use a spacer or cut the shroud and grind the fins to get it on?
 
I cut the airbox flloor out you need to take a lot out right back to the rear edge of the airfilter lip it's a very snug fit use the 92, 93/101 MC sloper manifold and you'll need to make a new throttle rod.
You can only run the auto oiler as the manual pushrod gets left out sorry.

If you do this mod on a SP125 no sweat use the standard rear mount
If you using a 101 then you will have to ue a steel cylinder housing off a 101 and drill and mount a SP125 rear mount to it.
The cylinder wether its a 101 or 125 is not modified for the airbox hotup

bdc_11a.jpg


v4d_454x339.jpg


Now you cannot fit a alky carb because there simply not the room.


McBob.
 
Last edited:

Thats fine and the right setup now gut the floor out of the airbox it's a snug fit width wise just be careful you don't file the sides and hole the fuel tank
You may need to use manifold gaskets and file the rear fin i didn't on mine it fitted just fine.

McBob.
 
Last edited:
Back
Top