tuning an indian 200 barrel

[simon k]

i want to bore out a 200 barrel to 68mm or 70mm, on inspection the transfers taper down towards the cylinder wall & when bored out this may move up towards the inlet. is a gap acceptable under the rings at bdc?

[rog60]

I had one bored out to 70mm and, as you say the inner wall of the transfers moved about.5cm up ther barrel. On fitting everyting seemed to be free, no rings catching etc but the engine would not start, could get occasional puffs of smoke from the exhaust and that was it! I don't know whether it was the barrel or something else but when I put the 66mm barrel back on engine fired staright away.

Hope you have better luck

[simon k]

thanks for the reply's. yes i'm refering to the area highlighted in red.