MTFCA Forum

I have assembled the cleaned L-4 brass body Kingston L-4 carburetor that I mentioned in last week's posting and have yet three questions. This is my first Kingston L-4 and the MTFCA carburetor booklet left a lot of unanswered questions.
(1) In various sources, the drain assembly is shown under the throttle intake (in front) and in others it is shown beneath the choke orifice (in back). I realize it will function in either orientation, but which is correct? Front or rear? Check out pictures in the MTFCA booklet, Bruce's "Bible", vendors' on-line photos and various issues of national club magazines. That drain valve is located all over the place! I had a a 50-50 chance of guessing correctly, as can be seen from the photos. 'Probably the other way, though, right?
(2) This is my first carb that doesn't have any jets! I have read the theory behind how this carb works with its air valve, but I am still a bit uncomfortable with this design. When the adjuster needle is turned down all the way until it bottoms out, is the hole at the bottom of the main body (see yellow arrow) supposed to be closed off? This one isn't. I can hear air blowing into the bowl even with the adjuster needle closed fully. Is this correct or should I be worried?
(3) As a follow-up to question #2, is this hole really left open like that? Nothing is missing? According to the exploded drawings of this carb, I can't find anything missing.
Thanks for your input. The carb goes back on the engine tomorrow.
Marshall[image][/image]

That hole in the bottom of the casting should be open, you aren't missing anything. As far as the location of the bowl drain, I have a pristine L-4 from Russ Potter on the shelf and its bowl drain is facing towards the carb mounting flange, as you show in your pictures.

If you are running engine splash pans on your car, perhaps the position of the carb drain hole in the splash pan can provide guidance on how to orient the bowl drain valve. If you don't run splash pans, then the position of the drain isn't as important.

I don't know whether the mixture needle is supposed to be long enough to completely block its seat or not, perhaps someone else can comment?

This older thread might prove useful: https://www.mtfca.com/discus/messages/5 ... 1468088785

"If you don't run splash pans, then the position of the drain isn't as important."

That's a good point, CudaMan. The driver's side of the engine has a ratty, rusty old splash pan (water pump leakage caused the ugliness there), but nothing on the side with the carburetor. Just gaping nothingness. You are right: the holes in the splash pan would be a good indication where the drain plug goes for most efficient draining. Too bad the pan is missing. I might have an old passenger's side splash apron lying around somewhere in the storage area. If I can find it, I'll use that as a final guide for drain plug's location, fore or aft. But what if there are TWO holes present that would accommodate the drain plug? Then, I guess Old Henry anticipated mechanics flipping the drain plug's location front to rear and made provisions for human error by added an extra "drain" hole in that splash pan.

Thanks for the verification of the drain plug's location. If Russ Potter placed it up front, I'm sure as heck not going to dispute that!

Marshall