Glad I was able to point you into the right direction on your sprocket size, 90mm 4 bolt pattern seems to show up a lot on our favorite brand of motorcycles
Hope the 43t works for you, I know when the 39t starts to fail I will slap on the 43t and be 'done'. The 39t is extreme, our 197cc barely has enough oomph* to run that gearing (17t front), and I only weigh 120lbs
*Bike runs ok but needed to be modded to run the 17t/39t sprockets (intake, exhaust, carb tuning out the yin yang...), with the 39t, 5th gear is now like having a 6th or maybe I jumped up to having a 7th gear in it's place
, anyone else able to go just shy of 50 fully wrung out in 3rd... no?.. it's only me?