McCulloch 4600 restoration

[Arrmon Lute]

Well I cannot get you any before pictures, but I will try to remember to take some pictures of the floor of the port later on. Most of the epoxies are ceramic or aluminium oxide based, as they dry they form a crystalline structure that is resistant to heat, quite hard, and fairly brittle.

 

[hotshot]

Well, I forgot to bring my SD card. But I did do some other work and got a lot done.

I cleaned the engine up, saw the plug was running lean and decided to take a further look into it. I took the engine all apart, cleaned it up in mineral spirits.

I found a new side cover with a functioning chain brake for $20, score! I ordered a new sprocket and piston ring on ebay, and I plastic welded up the broken recoil pulley.

I also assembled the engine without the ring, fabbed up a degree wheel and a piston stop and got my timing specs.
I'm looking at exhaust starting at 107* ATDC with a duration of 136 degrees, intake starting at 73* BTDC with a duration of 146*. Transfers open at 129* ATDC with a duration of 105* for a blowdown of 22*.

This seems to have a few odd things, one an intake duration longer than exhaust, and a short blowdown.

I raised the squish from .052 to .022. I'm going to use this for a work saw in various hardwoods, so I would like to lengthen the blowdown for more lugging power but I'm not quite sure how to do that without raising the exhaust and decreasing my power stroke...

Oh, and i found that a 12 point 16mm socket works excellent to remove the clutch.

I think your exhaust duration should be 146° too, not 136. (180-107)*2

 

[Arrmon Lute]

Yeah, you are right on that duration. Well I got a new recoil pulley, made a nylon spacer so the screw couldn't tighten down, and the little wings that engage the flywheel got the plastic nubs that engage the "cam" broken off. I drilled a hole straight through both of the wings and pushed roll pins in! After that I had no more issues with the recoil pulley. It took about 2 times tuning the carb to get the high setting right, about 4 for the low. She starts on every pull now, and I'm going logging tomorrow! After I find that deer

 

[Walter Glover]

Got a decent 4600 that needs a clutch drum and oiler gear. Seems all parts are unobtanium.
Plan on making a rim conversion and a new nylon gear. Hoping the machining is easy!

 

[Arrmon Lute]

Hey, it's been minute since I posted here but I just wanna say my 4600 is still running like a champ. I bought a little tach off of amazon and got her up to 12600 unloaded, you CAN bog her down but you have to be trying! I recommend porting to anyone who can follow the guides on this website and has some decent tools. I'm now looking for a 70-90cc McCulloch to work on and get into chainsaw milling a bit.

 

[dev06]

Hey, it's been minute since I posted here but I just wanna say my 4600 is still running like a champ. I bought a little tach off of amazon and got her up to 12600 unloaded, you CAN bog her down but you have to be trying! I recommend porting to anyone who can follow the guides on this website and has some decent tools. I'm now looking for a 70-90cc McCulloch to work on and get into chainsaw milling a bit.

Hey just got my hands on a Mac 4600. Fuel lines are rotted out, carb may need to be replaced. Wondering if you found any after market parts or if you had to salvage parts off other saws? Any help would be greatly appreciated , this is my first time trying to get a old saw going

 

[TBS]

Hey just got my hands on a Mac 4600. Fuel lines are rotted out, carb may need to be replaced. Wondering if you found any after market parts or if you had to salvage parts off other saws? Any help would be greatly appreciated , this is my first time trying to get a old saw going

The same saw was sold under Remington too.
https://www.jackssmallengines.com/j...gas-chainsaws/rm5118r-41by80ag983-41by80ag983