Building a SP125C / 101B Kart Saw

[blsnelling]

I'm thinking red engine cover, white fan housing, blue recoil, chrome screen, a red or chrome oil tank, and maybe a blue or black clutch cover. I wish had the software to play with this visually. That would be pretty cool.

On a more technical note, how is the crankcase side cover sealed? I have a thin metal shim in the gasket kit that goes behind it, but it wouldn't give an air tight seal.

 

[watsonr]

yamabond or any of the gasoline resistant stuff works. You said a thin shield goes between the case cover and the cylinder?

 

[Chopwood]

To those who actually have experiance: how do these karts compare to the modern big saws? I'm talking about 3120's and 88's. Dennis, what is your opinion? I have run a few 166's 2100's,SP125 and an 056mag2. I think the modern saws are better. If I am wrong, let me know.

 

[blsnelling]

yamabond or any of the gasoline resistant stuff works. You said a thin shield goes between the case cover and the cylinder?

I suspect it may be a shim used to set the endplay between crank bearings.

What are the two holes through the bore for the flywheel side crank seal?

 

[RandyMac]

To those who actually have experiance: how do these karts compare to the modern big saws? I'm talking about 3120's and 88's. Dennis, what is your opinion? I have run a few 166's 2100's,SP125 and an 056mag2. I think the modern saws are better. If I am wrong, let me know.

they would be left sulking in the weeds, slinking home looking over their shoulders.

 

[ozflea]

Thats about it Randy ...................

McBob.

 

[leeha]

I'm thinking red engine cover, white fan housing, blue recoil, chrome screen, a red or chrome oil tank, and maybe a blue or black clutch cover. I wish had the software to play with this visually. That would be pretty cool.

On a more technical note, how is the crankcase side cover sealed? I have a thin metal shim in the gasket kit that goes behind it, but it wouldn't give an air tight seal.

If you find a place to chrome Magnesium, Please let me know.
As far as i know it can't be done. All the chrome on the Mac
kart engines is over aluminum. If you notice the chrome flywheel
housing is much heavier than a painted one off a saw as well as
the block side cover. So i don't think you can chrome the oil tank.
But it sure would look good.

As for the shim, I have no idea. Mine did not have any shims.
I would call Terry on that one.



Lee

 

[leeha]

they would be left sulking in the weeds, slinking home looking over their shoulders.

Nuff said!!!!!!!!!!!!!!!!!!!!



Lee

 

[ozflea]

McCulloch Racing Engine sticker onm a 101 M/C see the decompressor Dennis

McBob.

 

[Ambull]

To those who actually have experiance: how do these karts compare to the modern big saws? I'm talking about 3120's and 88's. Dennis, what is your opinion? I have run a few 166's 2100's,SP125 and an 056mag2. I think the modern saws are better. If I am wrong, let me know.

A Stihl MS 880 is listed at 8.6 HP

A Husqvarna 3120XP is listed at 8.4 HP

IMO 101b you can expect at least 10HP, and there is room for quite a bit more.

As far as power goes, it is not even close. The 101b will cut at an engine speed far above the 9500 rpm rev limiter on a 3120xp.

 

[blsnelling]

McCulloch Racing Engine sticker

McBob.

I NEED one of those, lol

 

[blsnelling]

If you find a place to chrome Magnesium, Please let me know.
As far as i know it can't be done. All the chrome on the Mac
kart engines is over aluminum. If you notice the chrome flywheel
housing is much heavier than a painted one off a saw as well as
the block side cover. So i don't think you can chrome the oil tank.
But it sure would look good.

As for the shim, I have no idea. Mine did not have any shims.
I would call Terry on that one.



Lee

Well, I just got schooled, lol. So much for those ideas. Thanks for the info.

 

[Jacob J.]

I've talked to a couple motorcycle shops about chrome-plating Magnesium and I think it possible from what I've heard.

Typically what they do is either deposit a layer of copper electrolytically and then chrome on top of that or they use a chromate conversion finish
which is then polished. There's a couple of websites that claim to chrome-plate Mag.

Chrome Plating services on Plastic, FIberglasss, Magnesium, Metal,

Black Chrome Plating - Arlington Plating Company

 

[leeha]

I've talked to a couple motorcycle shops about chrome-plating Magnesium and I think it possible from what I've heard.

Typically what they do is either deposit a layer of copper electrolytically and then chrome on top of that or they use a chromate conversion finish
which is then polished. There's a couple of websites that claim to chrome-plate Mag.

Chrome Plating services on Plastic, FIberglasss, Magnesium, Metal,

Black Chrome Plating - Arlington Plating Company

Nice info Jacob, The couple chrome shops i have delt with
said they can't do it.
I will check them out. Although i bet it's very pricey.


Lee

 

[Jacob J.]

Nice info Jacob, The couple chrome shops i have delt with
said they can't do it.
I will check them out. Although i bet it's very pricey.


Lee

That's what I'm thinking. Although I can tell you, I'm highly tempted to go for that "Black Chrome"
on four or five of the big old saws I have, so if there's enough parts involved it may bring the price
down a bit.
A local guy that does powder coating cuts me a pretty big break because I wait until I have a lot of
parts to do at once and I also sand blast them and scrub them down with fresh paint thinner before
I bring them in.

 

[54stude]

I you are looking for a bare "patina" look from magnesium that will not turn chalky and get the white death, I have heard this gibbs brand penetrant works well.

Gibbs Brand penetrant

 

[Dennis Cahoon]

Lee, I saw a 2100 once that the owner polished the mag out and it looked just like crome. Lots of elbow grease, I would guess.

 

[Dennis Cahoon]

To those who actually have experiance: how do these karts compare to the modern big saws? I'm talking about 3120's and 88's. Dennis, what is your opinion? I have run a few 166's 2100's,SP125 and an 056mag2. I think the modern saws are better. If I am wrong, let me know.

I ported an 084 that I ran when I worked for Ericson helicopter that would smoke a 125 Mac. The 101's ran good but didn't last. In big wood getting 30 days without problems you were lucky. I didn't have 101's, but the 125's, I got rid of because they were a PITA to work on, and weren't that reliable for me. Most guys got away from them and the 2100 Homelites in the early 70's and went to 075 and 076's or 2100 Huskies. Except for a few diehards, the 125 faded away for smaller saws.

 

[ozflea]

Polishing a saw's alloy looks great but man you gotta work at to keep the shine heres my old Solo Twin.

Mc Solo Bob

 

[ozflea]

I ported an 084 that I ran when I worked for Ericson helicopter that would smoke a 125 Mac. The 101's ran good but didn't last. In big wood getting 30 days without problems you were lucky. I didn't have 101's, but the 125's, I got rid of because they were a PITA to work on, and weren't that reliable for me. Most guys got away from them and the 2100 Homelites in the early 70's and went to 075 and 076's or 2100 Huskies. Except for a few diehards, the 125 faded away for smaller saws.

Your right Dennis the old 125's are a bit labour intensive against the new released saws but hey thats life even Mac moved into vertical cylinders making life a dam site easier and quicker

101's where made to go not last a life time wear rates are high in kart engines.

McBob.