McCulloch Chain Saws

[Brian13]

Do some digging on kart sites. I can't remember where I saw them, but there are different thickness gaskets available. I have considered doing the same. You could also investigate "decking" the block like a car engine, same as milling the base on a modern saw cyl.

I used to do this on Kart engines in the 60s. There were also heads with smaller combustion chambers too. There were also strokers that NEEDED the real thick head gasket to keep the piston from hitting the head. The top ring stayed in the cylinder, but the piston top was above the top of the cylinder.

It will be a little while before I even get to this saw, but the head gasket is busted up and will need to be replaced. When I get down and dirty with it, I will measure the space between the piston and the squish band and see what I have. I sure I can make one if need be. I looked through the IPL for the S44A and another kart IPL and didnt see any choices for gasket thickness. Starting to think about bypassing a project or two to get to this one LOL.

 

[RandyMac]

My MC20's head gasket is about 1/3 the thickness of a 1-50. It sounds like a quick way to boost her up.

 

[Brian13]

I will look into the kart gaskets. The one I have looks to be about 1/16"ish.

 

[leeha]

A big thanks too LeeHa for sending me that Mac 700-series parts care package. It arrived this afternoon before work. They're just what Randy and I needed for our saws. His bottom bracket was badly broken in a few spots, and the one Lee sent is in fine shape. Those grills, screws, the fan cover, and the handlebar/bracket assembly will all go to good use. Thanks again Lee! You most certainly DO NOT "suck"...

Your very welcome Aaron.
Hope you and Randys saws are up
and running soon. If you need anything
else let me know.


Lee

 

[cpr]

If you're going to make your own gasket, I suggest copper over a beer can. Works great on the race engines...

Also, I'd avoid the temptation to reuse a metallic head gasket. My experience is that they are one-time-smash.

 

[Brian13]

I was thinking copper for the material. The beer can idea came from a friend that ran dirtbikes for awhile and was his suggestion. Also it is used for base gaskets a lot on the newer saws. The gasket on there is busted and has to be replaced so no worries on reusing it.

 

[Eccentric]

Got a McCulloch Super 250 on the way from MrBowSaw (Cliff). Yay! He says it has low compression, so I figure it at least needs new rings, if not a new piston, possibly an overbore. At least that's possible with McCullochs! Going to put in all new seals and gaskets (and possibly bearings) while I have it apart. Here's a couple of pics that Cliff sent me. I'll shoot some more once I receive the saw.

 

[willysmn]

MACs head gaskets

I will look into the kart gaskets. The one I have looks to be about 1/16"ish.

The thin gaskets were made of very soft aluminum, probably 1100, and were on the order of .005 to .010 inches. the stroked MC 10, which probably made it the same as a MC 20, was almost 1/8 inch as I remember.

 

[willysmn]

I was thinking copper for the material. The beer can idea came from a friend that ran dirtbikes for awhile and was his suggestion. Also it is used for base gaskets a lot on the newer saws. The gasket on there is busted and has to be replaced so no worries on reusing it.

Soft copper would work. Beer can aluminum is drawn, so it is fairly hard. There is not much give, so your head and cylinder have to be very flat and smooth. If you could get some soft copper or aluminum, either would work

 

[willysmn]

head gaskets

If you're going to make your own gasket, I suggest copper over a beer can. Works great on the race engines...

Also, I'd avoid the temptation to reuse a metallic head gasket. My experience is that they are one-time-smash.

Yes, they are one time smash. We did reuse them, when we had to. (Saturday nite before the race Sunday morning)

 

[67L36Driver]

Yes, they are one time smash. We did reuse them, when we had to. (Saturday nite before the race Sunday morning)

You can anneal them with a propane torch and reuse.

I used them last time I had the heads off my Corvair.

 

[rwoods]

Bar Interchange

Slot size aside, what 40" to 48" bar best interchanges on a SP125C - Stihl or Homelite or something else? I can handle the slot issue but I don't want to fool with the other issues. Of course, a reasonably priced MAC mount roller nose bar would be nice if I could find one. Thanks, Ron

 

[Wildman1024]

It's OK Cliff...Not like I wanted a Super 250 for myself :bang:

 

[Mr. Bow Saw]

It's OK Cliff...Not like I wanted a Super 250 for myself :bang:

ARRRR.You never said anything.:bang:

 

[RandyMac]

ARRRRR!!!!!!

HA haha Hey! Aaron! that yellow fever sunk it's shiny fangs pretty deep, eh? Yep total conversion in progress, com'n deny it.

 

[Wildman1024]

ARRRR.You never said anything.:bang:

LOL just busting on ya. I do need to get me some yellow here soon. What better saw to be my 1st mac then a Super 250.

 

[RandyMac]

lol just busting on ya. I do need to get me some yellow here soon. What better saw to be my 1st mac then a super 250.

a 795.

 

[Wildman1024]

a 795.

I'll be waiting for the mail man

 

[RandyMac]

I'll be waiting for the mail man

The next one I find.

 

[Teddy.Scout]

The next one I find.

I want to be on RandyMacs friend list!!!!!!!!!!!!!!!!!!!!!!!!!