McCulloch sp125 Rebuild

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HerbalSage

New Member
Sep 20, 2024
2
Highland Park MI
Just wanted to introduce myself as an up and coming hobby arborist. Been rebuilding from complete teardown on my sp125 I inherited from my Grandpa. I recently got it to roar a little after new piston. Was trying to figure out the modded Tillotson carb when I broke the starter spring coil. Which is not fun getting out I'll post what I do to torque the cap on the starter assembly.

This thing was tricky tricky to take apart. Assembly lube ended my nightmares on the needle bearings. The new Oem coil should be here on Monday. I'll make a video for Youtube and link it here. I got a 15-20 ft tall 24-36in round Norway Maple ready to fall after I spent the last two days topping it.

Soon I'll show my setup for a urban homesteader in Detroit. Very excited to use a wood stove for my first time this year.
[Hearth.com] McCulloch sp125 Rebuild
[Hearth.com] McCulloch sp125 Rebuild
[Hearth.com] McCulloch sp125 Rebuild
 
Hi and Welcome
Awesome saw...
If you ever decide that you want to rehome it let me know.
You should do a vacuum and pressure test on it before you run it.There is a reason the original piston was scored.
A vacuum,pressure test will tell you if the saw is sound to run.
Without doing so you run the risk of burning up the new piston.
Did you clean up the cylinder?
Enjoy the big old muscle saw
 
Hi and Welcome
Awesome saw...
If you ever decide that you want to rehome it let me know.
You should do a vacuum and pressure test on it before you run it.There is a reason the original piston was scored.
A vacuum,pressure test will tell you if the saw is sound to run.
Without doing so you run the risk of burning up the new piston.
Did you clean up the cylinder?
Enjoy the big old muscle saw
The cylinder barely had any transfer on it. I couldn't feel anything with my nail. I'm definitely keeping it to remember my grandpa and because it's probably one of the sickest saws on earth.

I think the piston is a combo of running too lean and something falling down the big carb hole. There is a slight scuff under the exhaust port of the chrome but otherwise its nothing too major.

I'll get it tested. Need to buy one for old times sake. It did the pull cord drop test pretty good. And like I said I got it to burp from adding fuel directly to the carb.