2 Hose Fittings On Mikuni Carb? HUGE PIC

[cody89]

I have a 1991 YZ 125 engine and has the stock original carb which is a Mikuni TM. I am not sure what the bottom feed is on the carb. The big one I am going to imagine is for fuel to go into the carb but I am not sure what the bottom one does.


http://i.imgur.com/GNxnd7G.jpg


Also, I noticed that this fuel line is bigger then the fuel line i have for the kart. would it be fine if I took the bigger hose and ran it from the pump to the carb but kept all the other fuel lines the smaller size?(tank to pump, pump to tank(return)).

 

[Oxymoron]

It's probably for the automatic oiler. You can just plug it off if you're just going to run premix.

 

[Doc Sprocket]

Overflow, I believe.

 

[anderkart]

Yep that's just your Bowl vent fitting, it would have just had like a short length of fuel line installed that wasn't connected to anything at the other end.

You can buy fuel line reducers at some auto parts stores. You'd need to measure what size you need, but here's a link to a 1/4" to 3/16" reducer avalible on ebay: http://www.ebay.com/itm/Fuel-Line-R...pt=Race_Car_Parts&hash=item33822d4283&vxp=mtr