Multi Grips [X(]

I froze the back plate, but the insert still won't budge.

The NVA screws into a boss on the top of the intake. the NVA jet enters the venturi through a hole in the insert, which secures what is otherwise an interference fit.

Using compression (such as soft jaw pliers) on the end buttress of the insert will probably result in the insert being forced out-of-round, compounding the problem.

The intake disc valve rotor is pinned to the back plate. Fortunately the pin is easily removable courtesy of a small pin locking screw which can be loosened.

I will remove the disc valve rotor and try to drive the venturi insert out using a suitably sized dowel, after applying a little heat to the exterior of the intake tube. I will need to firmly support the back plate for this procedure. A peice of hard wood with a drilled hole deep enough to allow for insert to back out should be suitable.

**

Small props or large, this engine is not happy on the large venturi insert. It "wanders" RPM's and will not hold a steady run at maximum setting. I'd wager it would not run steadily for stunt work.

I have made an intermediate sized venturi insert which I am keen to try.