Is this an oil injection port?

Brad William /

I assumed so but it does not go to the carburetor throat. It goes directly into the bowl via the channel visible below it. So is it a breather? Doesn't the overflow tube in the bowl (brass tube at very bottom of photo), that is always open to atmosphere, suffice to do this?

This is for premix. Should I plug this hole or not? Shouldn't matter either way if it only goes to the

It's a very nicely built little carb. But I'm surprised at how small it is. It's almost more compact than the 12mm bing and replaces it easily without hanging outboard. (edited)


Re: Is this an oil injection port?

The brass at the bottom of the bowl is likely the drain .

The vent you 'arrowed' is just that , a vent and should be tubed downward to empty below the motor and to the side of the rear wheel path .

Note that that tube has to kept clear and unplugged .

I've had mud daubers plug tubes and had me scratching my head as to why the motor wasn't running right . ;)

Re: Is this an oil injection port?

circled tube as pd sez, its just a breather, keeps the float bowl from pressurizing as it fills

brass tube at the bottom is the drain, it's opened by backing out (but not fully removing) the brass screw there on the bottom, that lets you drain the float bowl if you're pulling it off or if water got in there (water sinks to the bttom)

Re: Is this an oil injection port?

Brad William /

Ill try to post a pic of the inside of the bowl.

The brass tube at the bottom there goes to another vertical tube inside the bowl that rises above the fuel level. It is unaffected by the screw shown at the bottom. It is always open to atmosphere. It is certainly the overflow tube.

The large brass screw at the bottom is the drain itself.

It is a hollow bolt drilled crosswise so that it drains efficiently when only half backed out.

So the port that is pointed to in the photo is another vent? It opens directly above the bowl via a hole in the body of the carb.

I just want to be certain that it should not be capped off. (edited)

Re: Is this an oil injection port?

Brad William /

this is a pic from google images. same as mine


Re: Is this an oil injection port?

The float bowl over flow and drain ( screw ) use the same tube for drainage .

The port the OP has an arrow pointing at is a vent to atmosphere , so pressures stay the same in and out side the float bowl . The vent normally has a hose attached and runs downward , just aft the motor .

Do not cap the vent or the drain . ;) (edited)

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