Hello all,
I acquired a Thunder Tiger 46 Pro. The carb is shot so I was hoping to put a venturi and NVA in its place.

I do not really want to spend any money on it as it was part of a deal and not bought with any particular plane in mind. But, now that I have it I would like to see how it would run.

I have a number of various size venturi but the problem is they are all smaller than the opening in the case!

The question is, is it okay to, "Shim", the hole? I have read Randy say it is okay to use a sealer for a venturi but the gap is too great at the moment, I think.

Or, do I need a properly fitted venturi?

Many thanks in advance.
Craig

I have a number of various size venturi but the problem is they are all smaller than the opening in the case!

The question is, is it okay to, "Shim", the hole? I have read Randy say it is okay to use a sealer for a venturi but the gap is too great at the moment, I think.

   If it is "through the middle", i.e. the venturi is retained by a spraybar going through the case and the middle of the venturi, leaks don't matter that much, so shimming it will work OK. Make a tubular shim that goes around the tenon part, drill a hole through it from one side to the other, and use that to hold the shim and venturi in the case. Seal as necessary.

    If it's a "through the side", behind the venturi with a hole that lets fuel in through the wall of the venturi, then, you have a problem, and while you could probably devise a shim if you were very careful and precise, but the chances of it leaking the fuel between the tenon and the case are very high, with inconsistent results. Might be OK for ground testing.  This used happen almost all the time on ST46s and the PA is prone to the same issue, the RO-Jett slightly less so.

   Brett

If you get the proper venture and needle assembly no sealant is necessary.

I have a number of various size venturi but the problem is they are all smaller than the opening in the case!

The question is, is it okay to, "Shim", the hole? I have read Randy say it is okay to use a sealer for a venturi but the gap is too great at the moment, I think.

Whilst I turn up my own venturi's, sealing can be an issue! I generally resolve with a thin O ring between the crankcase intake opening and the venturi step, if compressed slightly before drilling the spraybar hole, it seals well. A loose venturi can be wrapped with PTFE tape to pack out the gap, even a bit oversize will still slide into the hole.

do u have a picture of your 19.i might have a replacement for it