
i think this is the one meant ... as usually i saved a pic and now cant remember anything about ..hope fully the pic will jog someones memory

i think the head and cylinder cowl hitting the frame would be a problem with to long a stroke, it looks nice but its just looks like a variation on a theme something totally new would be better twin shock, watercool option, larger wheel size .crankcase induction list is endless really a fully built motor is going to be in the region of 5k i would have thoughtwarts wrote:I understood that. I was just doing a thought experiment to get up to the 300cc you mentioned.
72 being the bore size on an RB250. Using the new 64mm stroke = 250cc, so same as.
75mm being the bore size needed to get 304cc with the 69mm stroke mentioned. Not necessarily possible.
You would need a bore of 77mm to net you 298cc with the std 64mm stroke.
Would a stroke job be perhaps easier to accommodate than an increase in bore? Unless there is sufficient room to jiggle a different barrel in there.
Perhaps a semi finished option? Machine your own stud/bolt position and crankcase mouth.
Maybe as short as long, but would the capability of a longer stroke have been fairly easy to design in before committing to metal?