Hi all,
One of the problem with stroking the NS crank is space for the big end, I noticed looking at the NSR250 engine when I stripped it that the NSR has a groove machined (or cast) round the inside of the crankcase to allow a 54mm stroke. I am considering if that will be possible on the NS crankcases.
as for motocross barrels CR250 - in fact most 250 mx bikes have a 72mm stroke - no chance of getting that out of the NS!
CR125 barrels are a possibility, there is one year of barrel that will fit straight on once the reed cage is cut down on the rear barrel
Matt - please let me know if you want to sell the NS400r crank or bottom end... cash waiting - I need one for 'experimenting with' to see if a stroke increase could be done.
Cheers, Mat.