Now here's a BS90 I haven't seen before

[RayK]

http://www.ebay.com.au/itm/Bridgestone-90cc-BS90-Kit-Parts-1967-Ad-japanese-book-/201044236886?pt=Motorcycles_Parts_Accessories&hash=item2ecf2b9a56

RayK

[paul]

This machine was discussed before on this web site.

[paul]

Looks like theres an optional "kit", seat, black exhaust, carb, cylinder, and wheel/tire assembly. SR/special racing parts maybe. The text shows 12.5 to 15.5, I wonder if thats the power output AFTER installing the kit. What does the technician appear to be doing?

[paul]

Anyone read Japanese, I think theres  mention of a 150 kph machine in the text. Lets see that   would be 90 miles per hour?

[disc_valve]

The parts shown in this brochure are all race kit parts. The race kit was made available in Japan soon after the BS90 was introduced, and the bike was very successful in the Japanese National race series for several years. The produced similar race kit parts for the BS50 Sport. That one put out 10.5 hp at (I think) 13,500 rpm. On that basis, 12.5 to 15 hp and a top speed of 150kph sounds about right for a BS90 with the full race kit.

Graham