my 75mm bored A12A in stock condition have considerably more torque than stock A12

D wrote:
You guys answered it all almost!
The kb10 is at 66hp its only 2hp off the a12 as a single carb setup.
An A12gx vs A10gx might be interesting both with oval port heads! :)

Although 10kg doesnt sound like much when you compare power to weight
of the single carb A10 from a KB10 vs the A12 then the A10 might win.

I personally prefer the A12 w/ 3.9 in my 1000 by along shot though :)
However my coupe with the A10 is a different experience than the VB10
its feels more sporty as you have to revv it more so requires a diff
driving style yet economy is incredible probably another 20% better.

A12 with 76mm bores cant go wrong though!

Id be more interested in comparing the most rare of all the A series egines

The A13 long and short stroke versions if they exist from past threads

eg
1289cc 77mm stroke and 73mm bores
vs
1270cc 70mm stroke and 76mm bores

is this rwhp or flywheel horsepower?