Hi, does anyone know if theres a way to tell the difference between a OS61RF Hanno Special MK1 and the MK2 version?
Externaly that is.

Thanks
Jason

Hello again Jason,
At my advanced age Hanno 61s were a long time ago,but I seem to remember that Mk2s were ringed(OK not a totally external sign), and Mk1s were not, but the (OS) piston had a little groove where you'd expect the ring to be.
I say OS piston because a lot of people changed to Nelson(Sometimes called Shadel) pistons and liners, either ABC or AAC.
Remember those LINES.
Regards,
Alan.

Thanks Alan and hope that premium bond win makes up for your loss last weekend!

Cheers
Jason

The most recognizable difference was the fuel pump design. The MK1 had a return line from the pump to the tank. The MK2 a simpler design with just a fuel line from tank to pump, and pump to carb

Thanks for the reply's
Are you sure about the pump on the Mark 1 hanno?
I know the predecessor to the Hanno Special, the OS 61RFP had the pump with the 4 nipples, 2 to the carb and 2 to the tanks...because ive still got one!

Rgds
Jason