OK, here is a basic conversion for EVO 26 Gasser engine Carb flange to fit the 160FX.

The original flange:



I drilled out the original flange with a 15mm drill bit:







Then I cut away the remaining throat with a metal saw on the drill bit:



I cleaned up the remaining burr with a sanding paper dremel bit:





Now its time for the new 15mm throat.
I bought a piece of 15mm OD and 13mm ID stainless steel pipe.
The reason I chose steel was the tapping would be more durable than aluminum as its only 2mm at each end.



And the 17mm long steel throat gets into the carb flange throat nice and snug.



There is no easy way to bind aluminum to stainless steel,
so I mixed up a small amount of Devcon Steel epoxy (same as JB Weld) and applied to the joining surfaces.
A small amount is more than enough to hold them together and seal for any airleaks.



Then I positioned the flange on the engine, marked the places to be tapped for mounting the flange on the engine from sides, then drill & tap away.

Its important to mark the points to be drilled before putting on the O-ring as it should crush between the engine throat and flange; and seal nicely.

Unfortunalety electricity went out last night because of the storm, before I could finish the job. I couldnt do the back-plate tapping for pump pressure. No trials today..

I'll finish up the back plate pressure fitting job asap and hook up the walbro carb and give it a try in a couple of days.