I am finishing my GP Piper J3 Cub 40 ARF (beautiful ARF might I add) and I want to install my Du-Bro Fueling Valve. I have been modeling for years and I have always tried to position the tank appropriately in-line with the carburator. The engine I installed is a new Saito 65 4-stroke. My question: Do I have to be concerned with keeping the fueling valve in-line horizontally between the tank and carb, or to keep the gorgeous lines clean, could I install the filler on the fuse bottom with the on/off switch? I realize fluid dynamics would cause the fuel to level off at the tank level even if the line routed down to the fuse floor, but should I be concerned at all with any negative impact on the fuel draw.

Thanks a million guys and gals....................

Len
Winnipeg, MB (and yes, it is da#n cold here right now)

Fuel draw would be fine, but while filling or draining, you'll have a lot of fuel on the ground due to the low position of the filler.

I personally had limited success with fill valves. If they don't leak now, they will later.

I use 3 line tanks with the 3rd line to a clunk and a piece of tubing that's capped off.

You can hide this fill/drain line somewhere out of sight when not in use, and it won't leak.

My fear with this method is carb flooding when filling. Do you just dial-in the needle valve when filling?

Thanks for the feed-back pettit

Len

Hi Len,

I have been using DUBRO fuel valves for years without any problems, (other than misplacing the connector, but then I'm a forgetful old fart). I currently have them fitted to two models.

Using an inverted OS108 with the fuel valve on the lower third of the cowl there is no discernible difference to one mounted at needle valve level on a side mounted ST75, both work fine. I do change the tubing each seson though, (cheap deadstick insurance).

Hope this helps.

Cheers,

Colin

Thanks Colin, I managed to mount it pretty well in-line and it looks OK. I've been using the DuBro fillers for years as well, and I have about 4 "extra" connectors in my flight box.

Thanks for the feedback.

Len

Hi!
Why use a filler valve when it is so easy just to have a third fuel line hanging down under the cowl for filling the tank!?

regards!
Jan K
Sweden

Hi Jan,

As I mentioned above, in order to use the 3rd line you have to pinch-off the line to the carb or close the needle valve so you don't flood the engine. I guess I'm just a fuss nut, and doing my part to keep DuBro and my LHS in business.

Len

Hi!
No! you don't have to pinch off the line to the carb! On all my models having cowled in engines I use the the third line for fueling. All you have to do is to throttle down ...have the carb set to idle ..this will prevent fuel coming inte the carb... that easy!

Regards!
Jan K
Sweden

It is not necessary to pinch-off the line to the carb if you fill the tank via the 3rd line. I don't do it when filling all my inverted four strokes, and I don't recall getting any engine flooded. Fuel likes to take the path of least resistance, so it will flow to the tank.

How about using a fuel dot on the third line and place the fuel dot where the fuel filler is on the real J-3?

Rich

Yes, that what I would do.