Back on the K&B 61 for a sec....
I have 6 of them....not the Twister model...5 of them were run out and locked up....I bought them over several years averaging $3 each and sent them to Clarence Lee for rebuild and for the PDP mod.
I got a couple of Perry carbs and tossed the K&B carbs.
Right now I have one on a radio test airplane and trainer for friends.
I bought a VECO 61 back in 65' (engine in the pix) when they first came out and I wore it out so many times that I took it to K&B and had a 'max' repair...which was a new engine for $45.
I bought another VECO in 67' and it is still NIB.
A couple of them have the Perry backplate pump with the Perry pump carb and PDP mod. They are pretty strong considering everything.
They run great on 15% nitro and 18% straight castor.
They dont like straight synthetic oil.
Anyway..the rebuild cost averages about $40....git it while you can....I have still another one a guy gave me I need to send in.

I still have the wing from this Kaos and the plans too....it is the original Bridi version I built in 69'....gotta build another fuse and stab.

But....while these engines are plentiful...they probably are a bit too old for our intended use on CPA airplanes.
I'm still for the Rossi/AXI and NovaRossi.