Two 1960s Yoshimura Hondas

[rbaselt]

Here are photos of two Yoshimura road-racing Hondas that came to the US in the early 1960s. Both appear to have CR72 tanks, seats, front and rear brakes, megaphones, tachometers and front fenders. Not sure about the frames, possibly modified CB items? Does anyone have any details of the engine specs? --Randall

http://www.vintagebike.co.uk/Bike%20Dir ... himura.htm
http://tinyurl.com/yhbptmg

[rbaselt]

A colleague in the UK sent a 4 page article from the Feb 2003 Classic Mechanics describing the restoration of the first bike. Turns out it arrived from the U.S. without an engine! I can't upload the article since it is too large, but will email it to anyone who is interested.

Attached is a brochure from the early 1960s describing the upgrade items available from Yoshimura.
--Randall

[teazer]

Thanks Randall,
It's always interesting to read about the good old days and Pops sure knew how to make those bikes fly. When I built my first CB77 racer I remember reading through that stuff looking for the key to success.

Pops is spot on about reducing reciprocating mass. I had one motor with big light valves and several with stock but lightened valves. the one with teh lightest valves revved higher and smoother. The fact that the ports didn't allow the motor to make much power above 10.5 was a moot point with a road based 3 speed trans ( first was only used to get off the line).

For Winton I used to overgear it so that second and third were more useful on the twisty bits (99% of the track) and never used first or top after we gor moving. I'd get the holeshot most times and made the other guys work at passing me and with my erratic trace lines, that wasn't always easy.

There's always new stuff to add to the body of knowledge, but anything that Pops did was a great place to start.