It was intended for DF use. Yes that's a pump. It was designed to run upwards of 20K RPM. Not exactly sure how high in the 20's. K&B called it a 7.5, for its 7.5cc displacement. Doesn't it say 7.5 on the right side?

I have one that the late Bill Wisniewsky, who was still working at K&B, modified for me. I was going to use it in a 40-size SWRA warbird racer. I ran into Bill at the Nats, asked him about the engine and told him what I planned to do with it. He said it had a 2-piece crank and that it would eventually break. He said the trick setup was to install a 1-piece boat crank in it, lose the pump and use a 60-size nitro pipe w/muffler pressure; prop it for 18K on the ground.

I wound up sending it to him and he made the changes, sent it back to me. It looks kind of funny because the front housing is rotated 90 degrees CW to accommodate the intake timing of the boat crank. I forgot all about it until I saw your post.

CR

Edited for spelling and typos (grin), CR