Chainsaw Repair

The reason behind the Bango bolt as Al stated was to keep the head on as once the engine was given not only a radical port job and rebore they were prone to blowing their stack same as the macs.

Mac Girdle kits
http://macbobaust.com/mcgirdle.html

Besides Westbend or US motors offered a replacement 60 thou oversize piston to suit the 820 engine that's when fitting the girdle became important

McBob

I don't recall ever seeing a Mac engine with banjo bolts but have no doubt there were some .Horstmen or Wiseco made an overbore piston for some model of McCulloch up to 100 thou over  size .Usualy though on a rebore they took it up 2 to 5 thou .Whatever it took to clean up the cylinder .

Now on the 100 thou over I'm not certain if they put in a new sleeve or not because 100 thou would not leave much meat left on the cylinder wall ..I doubt seriously if that size overbore was used much .

They had stroker full circle crankshafts and just all kinds of goodies that are nearly nonexistant today .

The life of a full blown kart engine was normally less than one hour total running time between rebuilds .Less if they came apart like a dollar watch which they did on occasion .It was just unbelievable how much power they could get out of them and that was 50 years ago .

Brings back memories.
I have one of those Power Products AH-82 engines.
Think is all stock . The thing has been in the garage attic 
at my parents house for 40 years or better.
I have not even thought about it for years till I seen this post on carts.

Time to get it out and do something with it.

In my area there used to be a few kart tracks.  One was even about 3-4 miles from my house..............but shut down by the time I was 4-5 years old.  It's been the location of a large 'flea market' ever since.  I can remember going to the flea market and seeing neglected karts in the weeds on the other side of a fence.  They were 'cleaned out' (probably scrapped) shortly after that.  I also remember a kart shop (ran out of a guy's garage).  He shut down around 1982 or so.  He had racks of McCulloch kart engines...

'Vintage' karts and parts pop up on my local CL from time to time.  Always more than I want to spend however.  I'm also a bit too heavy to be competitive now.