Don't know about the GPS I'm afraid, but I do know you won't be getting good power with the PV set up like that. It is meant to remain closed at low rpm, and open for high rpm, giving good power at all revs.
Dave, yep, it's a bit gutless right off the bottom - and I have owned a few 2-strokes in my time.
Looks like I will have to hold off on some of the bling until I get the important bits sorted first. The 'To do' list:
Crank - at 36K it's on borrowed time. Are rebuilds worth it (how do rods hold up over time? I have access to all the bearings/seals), or should I just take the plunge for a new one?
Top end. Head/barrel swap for front cyl. I was going to replace the single ring RM pistons with OEM Honda.
GPS - get a new one, wire splice it.
Servo - test the spare one and hope it works (and that it's not the PGM).
A few things to work through - I hope the advice keeps coming.