The owner of this Thunderbird bought it in with a full system onboard (not jetted for) and running really rough. It had two problems – definitely it needed setting up for the pipe, but also because it had been run lean for a time the three old-fashioned HT coils had cooked up and broken down, because of the excess heat generated by harder working (than they should) spark plugs.
This is a common issue on Trumpets of this age so on went 3 new coil packs. We could then set up the jetting… and blimey, it ran like a dream once it was getting the right combination of spark and fuel/air mixture. Lovely bike, and lovely job!
Dodgy ignition packs and lean fuelling – all sorted now…
