New Carb Question By defrogi (Read 1,088 times)

[defrogi]

I got a new 23mm carb for my 4 stroke 50cc scoot. It has a 52mm big bore kit with performance head and cam, performance air filter, no rev limit CDI - high output coil, iridium plug, performance exhaust, performance variator and clutch, Dr. Pulley 6g sliders and a Bad Boy horn that is bad to the bone!

The new carb has a brass tube with a plastic cap that I can't figure out what it is for. There is a hose connected to the bowl drain port and a hose connected to the fuel line in. I got the carb from Scrappy Dog and have emailed them asking this same question but have not as yet received a response. I also posted this on the ScootDawg forum and no one seems to know the answer yet. Here are pics of the carb.

This is the tube in question.


Yellow outline is fuel line. Red outline is bowl drain line.

This is a pic of the bottom of the carb.

[zugzug]

Its hard to tell for sure from the pics but its probably just a vent. A lot of the old I4s used to have a vent tube and then when the emmissons became an issue a lot of them had the vents running thru some sort of filter system. The best way to tell is to pull off the bowl and see if it runs to a port (opening with no type of valve/jet) in the fuel bowl area.

[defrogi]

It turns out the brass tube with the cap IS the fuel line and the "other" brass tube with a hose on it is for emissions and I put the plastic cap from the fuel line on that tube and everything is working great!

[Alleyoop]

Defrogi,
Great ending to a puzzleing question. As they say Live and Learn and we all did on this one.
Alleyoop

[Bashan]

Great pics and nice post Defrogi, thanks. Alley's right, we need to bank this one for future reference. Zugger was right again....CURSES! . Kidding, you know we love you Zugster. Hey Defrogi, how did you get those elliptical outlines on your images? Did you transfer it back to paint and then to the bucket? That's a real PITA. Rich