Robert Groves

Thanks Bob

I will be putting the stock muffler on and taking readings with 12x6, 12x8 APC, 12x8 13x6 MAS, then the same with the ultrathrust.
Then playing with castol fuel and an Os8 plug.

The other anomile that can be playing funny with me is the adaptor plate. UT no longer makes a size to fit the ST90, so an adaptor plate is needed. The one I made lines the pipe and exhaust perfectly, but is wider than both on the one side. Bob,could this be affecting the pipe performance? I am talking 5mm here

Thanks
Rob