Mikuni Super BN 38

[2kdime]

So work is progressing and Im looking at this thing

Looked at the manual online and mentions nothing of this

But looking at the picture below

The carb has a built in pump, and will get its pulse from the carb adapter

The small barb at the bottom is for a primer, and will be plugged/capped

One of the larger ones is the fuel IN

The other one is a fuel RETURN

Whats everybody do with that one?

Cap it? Return to the gas tank? Tie it back into the fuel in line? Run a line to the bottom of the bike?

Thanks in advance guys

 

[Motra]

That's a Jet Ski carb. The return line went back to the fuel tank. They did that so there's always an adequate supply of fuel in the carb for any condition and at any angle. The fuel pump simply pumped too much fuel so the excess fuel flowed back to the tank. It's a big carb for a 200cc class engine, or are you running a bigger engine?

 

[2kdime]

Gx390

Ported and polished with 40mm/35mm

And some other goodies

 

[2kdime]

So back to the gas tank then?

Would using a T before the IN side and then running this RETURN side into that T cause any issues?

 

[mipowdercoater]

that carb feeds 550cc twin cylinder jetski's not a 4 stroke its gonna be hard as hell to tune stick to tried and true
Mikuni 32mm TM Flat Slide Smoothbore Carburetor Carb | eBay