I just ordered a twin spark BTH for another racer and I never had and issue with the first one, which is still racing. The BTH is quite easy to set and Vibrac has spoken about this before. There is some play in the rod when it is inserted through the armatur, but I do not think it makes a big difference to the performance as long as you: 1) know about it, and 2) set it using the same technique every time. I found that after you insert the rod if you take the slack out of the system by moving the rear wheel in the direction of travel, that was where the spark occurred.
I think I would try lapping in the taper and spend the rest of my money on some new springs. With a single you can store the bike for long periods with the valves closed, but it is harder to do on a twin. This means that often some of the springs are compressed during storage, which can take a toll of the years.
David
I think I would try lapping in the taper and spend the rest of my money on some new springs. With a single you can store the bike for long periods with the valves closed, but it is harder to do on a twin. This means that often some of the springs are compressed during storage, which can take a toll of the years.
David