Need quick help with petcock and carb set up.

[Stalin321]

Hi, I recently purchased a cb750 petcock to replace my old 75 kawasaki kz400s one.

here is the problem I'm having. I've been trying to figure out which one of the outlets is the vacuum one.

does cb750 petcock have two outgoing fuel lines and no vacuum lines?

Also, my carb is a 98 CR125 35mm keihin if that matters, its a single carb conversion.

I had both outlets connected to a Y joint to the carb and it would run on with the choke on, but once I drop the choke, the bike dies after a little while. I'm guessing its because it runs out of gas in the carb bowl.

so the other question is, how can I make a 74 cb750 petcock work with the cr125 keihin so that the bike stays running?

 

[lingo]

The cb750 petcock does have 2 fuel outlets and doesn't have vacuum line.

did you plug the vacuum port on the motor? that would be ahuge vacuum leak and would explain why it would run the choke on but not with the choke off

 

[Stalin321]

that could be it...I'll go head and check it out.

it runs with no choke on but only for a bit, then dies...

you're talking about the breather tube port right? sorry I'm a noob to bikes.

 

[Stalin321]

ok, it's still not running...rpm jumping around.

i got the engine port sealed off. im also running short pipes with no muff, could that also be one of the reasons?