Just a brief update. Back on the dyno today, coolant leak did not reappear and the bike ran well. We were able to re jet it and set the timing. Still rich at 11.5:1 and fairly stable for all three cylinders.
We ran the bike to 9000RPM, it made 98.6HP at 7500, this was a peak indicated reading then it dropped off dramatically by 25 hp at 7600RPM. Looking at rear wheel speed and RPM the clutch is starting to slip at 7500RPM. Will remove plates and glass blast both frictions and steels and try heavier clutch springs to try and get it to hold.
Made several pulls, the clutch problem became more evident when dyno pulls were back to back or as the clutch heated up. Got the best result after sitting for a while but was slipping at 98.6HP.
Pleased with the results.