We recently acquired a 4 cycle jackshaft and my two cycle experience is almost useless and has my head spinning. I keep seeing 1-1 primary ratios so guys can run shorter chains but we want to use it so we can get high final ratios without dragging a big rear gear. I don’t like the idea of a clutch being crank mounted because heat on chain primaries is atrocious. But let’s say we do a 1.75 primary and we put that clutch on the secondary for an open modified. That clutch needs to hit at 4500-5000 engine rpms, but the primary makes the jackshaft speed engagement for the clutch be in the high 2000’s. Is that even achievable? What are you guys doing to get small gears with big short track ratios?