I've found some pics of the other KMD. This belongs to Rex and I think that it's a hybrid of several separate engines. It broke a piston while it was going very well in a Diesel Goodyear model. We have a speed limited competition here for such engines/models. The KMD was right on the money and up there with the Fora, Parra, PAWs Oliver Tigers etc. I suspect that it's running again.
Even though the venturi hole is seriously obstructed by the non standard Needle Valve Assembly it still performed very well
I won't see Bob or Rex now till next Saturday but when I do I'll ask about your problem.