DECEMBER 2015 Mini Bike of the Month, CarPlayLB's "Home Run" 1960s Quarter Horse

[LSCustoms]

The December 2015 Mini Bike of the Month is CarplayLB's "Home Run" 1960s Quarter Horse

 

[LSCustoms]

A bit of history and information on this bike as follows:

Quarter Horse minibikes were made by a company called “Micro-Sound” in Los Angeles in the early sixties. It is rumored that the retail price was approx. $800 at that time, perhaps making it one of the most expensive minibikes of its time. After tearing this QH apart and rebuilding, I understand why! Very high quality parts were used throughout and the engineering is amazing! A patent search also yielded two patents that were granted for this design. Rumor has it that the frame section of the bike, which doubles as the fuel tank, was sourced from WWII surplus mortar shells. I cannot confirm this, but a quick inspection makes it plausible!


I worked my backside off getting this! I made a deal to trade labor, parts, and cash…and it became mine! Be careful what you ask for! This roller was rough, but I had a vision! First thing I did when I got this home was to see if the frame would still hold fuel. Because the bike had not been run for a very long time and was without the correct McCulloch MC9, I stuck a garden hose through the top filler that resides under the tilting seat. Every seam in the tank/frame leaked. It looked like a sprinkler! As it had a lot of rust and varnish inside, I decided to have it acid dipped. Not a cheap endeavor, but it cleans it up nice!

I have a welder friend that has done aircraft manufacturing. He was amazed at the precision of the very fine, thin welds and had no idea this level of quality was done in the early sixties. Ron worked on this for about a month. When I picked it up, we ran the hose again. Still leaked! Another month and we were sealed and ready!

At this point I was ready for the CarPlay touch. I am a fan of powder coat and chrome, with a splash of polished aluminum! Resto-mod is the way for me! The two stage powder coating looks better than my pictures could capture. It is a very nice deep copper color. The steel parts were chromed, and the swingarm was polished. I do like my shiny! I wanted more a of a road bike feel for this, so I put the street tread tires on the polished wheels. The tapered wheel bearings were in great shape and I just cleaned and repacked them.

 

[LSCustoms]

more info:

Part of the design was to make this bike solid and easy to use. One aspect of that is the location of the jackshaft. It shares the same mounting point as the swingarm, eliminating the need for a chain tensioner as everything swings in the same arc. The caged needle bearings of the jackshaft sprockets ride on a hardened steel bushing. The two gears interlock. The seat was done in textured vinyl, but the seat base is untouched. It still has the original sticker that lists the three engine options, the MC9, West Bend 610, and the AH58, with their respective oil/gas ratios for the fuel mix.

In my search for power, I came across this McCulloch MC91 M/C. It had additional appeal as it has a ¾” PTO!...and the price was very right! The motor had a ton of compression, so I installed a compression release and a larger chambered head. The older Mac’s came with what’s called a “large flatback” carb. Parts are not easy to find and they have some issues with applications that are not like karts. I changed this to a Tillotson HL series carb spec’d by EC Birt with an adapter from Vince Hughes. I was able to send this motor to a gentleman named Scott Kneisel to have him do his magic. Scott is a new member here and an amazing mechanic…and a good person too! A few days was all it took Scott as the engine was in good shape.

Originally I had this whole engine polished. It looked fantastic…for about a week! What I have found out is that these blower housings were made from magnesium. The oxidation starts at the first blink and does not stop! After one month you could catch a finger nail in it! Dan-E-Boy came to the rescue with a paint job of sparkle silver that looks fantastic! With the clutch open to see, I thought a trick Cheetah kart clutch was the ticket.

After looking at as many pics as I could find in regards to the exhaust, I knew I had to build one! Not one to leave things “stockish”, I came up with the idea to use a baseball bat coupled to a stock chainsaw muffler…and end that with a curved tip. Baseball bats are plentiful, cheap, and high quality aluminum. Some have compatibility issues as far as welding goes, but this one was good! Ron the welder once again shook his head. I know his “inside voice” was saying this guy is crazy! It came out very nice and a quick polish later, we have the “Home Run” part of the “Home Run” Quarter Horse!

It has taken a couple years to get this one done…had to write this one into the household budget! I would like to thank my wife for putting up with my obsession! She has the patience of a saint and should make me sleep in the garage...but I probably would!