Bike of the Month - June 2012
1976 Honda RC125 Replica

Tom Ewing

Naples, FL



Here’s the pictures, and the scoop on the RC Replica.


I first started researching this project about two years ago. I ran across some 1975 pictures of Pierre Karsmakers testing an RC125 for the Honda Factory Race Team. I can only speculate as to what was being done with this test bike, but I presume that Karsmakers was either testing mods for Marty Smith’s “Type 1” RC125, or he was testing new technology for the upcoming “Type 2”.


The RC125 went through many modifications during the two(+) years that it was used in competition, and the particular bike he was testing was noticeably different than the “Type 1” we had become accustomed to seeing. Most noticeable was the cantilevered rear shock mounting. I really liked the look of this bike, and decided to use it as the model for my RC125 replica.


I started out with a stock 1976 CR125, and began the process of stripping it. The tank, swingarm, airbox, shocks, rims, fork tubes, pipe, carburetor, and many, many other parts went straight to the dumpster. The following is a partial (strong emphasis on partial) list of modifications that were made.

Emler / FMF provided the piston and cylinder porting
RC-style up-pipe from Nara, Japan
Custom tank
Custom built airbox to accommodate the up-pipe
Swingarm modified from original 1975 FMF
Forks extended 1.75”
For obvious reasons, no attempt was made to replicate the reed intake/injection system
Cosmetically, nothing was left untouched – Concours D’elegance level restoration (some of the pictures are shown in various stages of restoration, unfinished)
WAY too many other mods to mention

I have declared the restoration complete, but I plan to make a few more modifications at some point in the future to enhance the authenticity. I plan to custom fabricate a new left side stator cover and chain guard to match the RC125. I will also keep looking for a center-port (exhaust) cylinder. Once I find it, I’ll modify the up-pipe and split the frame down-tube to accommodate the center port cylinder.

The leathers shown the picture are most assuredly one of the last remaining sets of never-worn, mint, NOS “Marty Smith” Hondaline goatskin leathers in existence. I won them at Lake Whitney in 1976, and never used them (I was on a YZ125 at the time). They have been safely tucked away in a suitcase in my closet for the past 36 years – until I brought them out for the photographs.

The RC125 replica is now the alpha-dog of my collection of 1971-1976 motocross bikes. I am now doing a full restoration on a 1975 Kawasaki KX125. Nothing special, and they seldom earned a podium finish – but I always thought they looked cool. Next on the restoration list is a Pomeroy replica Pursang and a Mikkola replica Husky.