Full rebuild on a 123cc mac

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leeha

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I found this saw on CL. Guy was willing to ship so i went with it.
Got it this week and had it running but it needed a carb kit. So i
went to work on it today and was giving it a good cleaning. I pulled
the clutch and low and behold found this junk crankshaft. **** i
said. Now what. Well i had a spare block assembly so i robbed
the crank and went forward with a full rebuild. More pic's to follow.


Lee


RebuildingtheSuper797001.jpg


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Here's a pic of how i press the crank bearings without the outer race
comeing off. These bearingsa have a split race and will come appart.
Good used crank with new bearings installed as well as a new std.
piston and rings.


Lee


RebuildingtheSuper797008.jpg

RebuildingtheSuper797007.jpg

RebuildingtheSuper797006.jpg
 
Here the side cover is on.
I chose to install the two seals first and also
install the points & condenser. Then once installed
you just have to set the points and install the other
4 screws to hold the cover on and your done.
Note the correct oriantation of the wires and outer seal.

Lee

RebuildingtheSuper797013.jpg

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Last edited:
I then installed the pto seal. It helps to wrap the crank with
tape. There is quite a sholder on these cranks. Don't want to
ruin a seal lip. Clutch and muffler installed as well.

Lee

RebuildingtheSuper797015.jpg

RebuildingtheSuper797014.jpg
 
Saw is pretty close to being done. Flywheel and coil
are on as well as the covers. I had to install a new
cylinder cover as it was missing. just have to rebuild
the SDC carb and she should make smoke.
This rebuild got used crank, all new bearings, seals,
gaskets, points & cond. piston assembly and carb kit.
Should be another great running Super 797.

Lee

RebuildingtheSuper797017.jpg

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Another nice build/ thread Lee. Wish you were my neighbor! Love watching your builds and admire your collection. Especially those Alpinas!
 
Could it be rewelded then machined? Or not worth it?

It could probably be done but to me not worth the cost.

Another nice build/ thread Lee. Wish you were my neighbor! Love watching your builds and admire your collection. Especially those Alpinas!


Thanks Buddy.



Lee
 
Good to see another rebuild. I enjoy seeing the engineering of those old macs.
 
Lee, thats not the 100+cc MAC that was in the Hudson Valley Craigslist was it? Guy lives in PA just over the NY border?? I know what he was asking and would be pretty pissed If thats the shape the crank was in and he didn't disclose that.

Well any way you did a great job bringing it back into tip top shape. :clap:
 
Great was as always Lee.

Nice tip on the bearing removal, I have not had one come apart like that but I will know what to do in case I encounter the situation.

Mark

If they do come apart and you're stuck with the inner race on the crank, just take an air hammer and put the end of the crank on a block of wood and the air hammer will vibrate that inner race right off. Preheating the crank helps too.
 
Lee, thats not the 100+cc MAC that was in the Hudson Valley Craigslist was it? Guy lives in PA just over the NY border?? I know what he was asking and would be pretty pissed If thats the shape the crank was in and he didn't disclose that.

Well any way you did a great job bringing it back into tip top shape. :clap:

This saw came from Ill.
And i need to thank the fellow member that gave me the tip.
Thanks Buddy, You know who you are.
The price was reasonable so i'm not to upset. Just bummed a bit.


Thanks guys, I got the carb done but it's a bit late
to fire it off.



Lee
 
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