Antares100

My Feedback: (12)

Hi All,
Out of Nostalgia I picked up a Royal .25 (early model, name is cast into the cylinder, not added on) on e-Bay. I usually check the pics well before I buy, but missed the idle screw that was missing. No problem, right? Went to the hardware store, 15 minutes later, out w/a 3 mm machine screw and 2 nuts. After taking a look at the milled channel the screw guides the intake, it seems that it just locks in the a "setting" of air/fuel mixture allowed for your low idle. Don't know why but thought it was/did more than that.
I also looked at a couple of old parts I had and noticed the idle screw is tapered at the end going into the carb on the old part..
It almost seems like the ide screw is simply a set-stop for the closing of the carb for setting the idle. Can someone confirm that? I don't think the regular (not tapered) machine screw will have a problem, except perhaps with possibly an air leak. Just wondering if in general that's the way idle screws work (being a stop for the carb barrel) and if you think the non-tapered screw would suffice. Thanks in advance.
Antares100

Dick T.

My Feedback: (243)

If it is just the idle stop screw you should be fine. The idle mixture screw is usually tapered and goes into the side of the carb barrel that rotates open-closed.

Should not be any air leakage either as the stop screw performs no other function.

Antares100

My Feedback: (12)

Thanks for the response, Dick. That's what it seems to be, but always worth asking the question.