I have helibars and a 19mm genmar. I would say that new hydraulic lines would be needed for the 1 1/4 genmar. I had just enough slack in the brake line after removing the bolt for the clamp on the front forks. My controls just touch the windscreen at full lock (ZG sport touring) The left side at full lock will turn on my flash to pass switch. I would email genmar mfg. about this, they could probably tell you about the 1 1/4 ( they did for me about the 19mm) . As far as plugging the holes, good question. I've been gonna check Lowes, home depot, etc. for something , but never did. Also plugs from body panels, at auto body supply shops may work..??