1993 Kawasaki Vulcan running oddly

[Jeffsg605]

I cleaned the tank and the fuel petcock. Its better but doesn't like to rev past 5k rpm. Then if I do get it to rev past 5k, if I pull in the clutch, the rpms get really low, sometimes enough to kill it. I'm at my wits end with this bike. Its driving me crazy. Nothing seems to work.
My next step is to replace the fuel lines going to the carbs and check the float level. I never messed with the internals of the carbs, but I'm at a total loss here.

[GS_in_CO]

I cleaned the tank and the fuel petcock. Its better but doesn't like to rev past 5k rpm. Then if I do get it to rev past 5k, if I pull in the clutch, the rpms get really low, sometimes enough to kill it. I'm at my wits end with this bike. Its driving me crazy. Nothing seems to work.
My next step is to replace the fuel lines going to the carbs and check the float level. I never messed with the internals of the carbs, but I'm at a total loss here.

Start by just dropping the bowls off the carbs and see what's in there. If you have debris that's the thing to work on. If they are real clean it's probably something else.

[Jeffsg605]

I got the bike working perfectly today. Each carb has a vent hose that goes from the float bowls to a T-fitting and then there is a hose from that which is supposed to go into the right side air box. When I bought the bike, somebody stuck a screw in it to plug it up and it ran perfect so I didn't think much of it. On a whim I just took the screw out and it ran absolutely fine. When I plug it, it runs like crap. When I put it in to the right side air box as the manual says to do, it runs like crap. But when I let it hang there, it runs perfect.

So I have no idea how it was running before with the screw in it so well but it was. Also I think if I'm going to let it just hang there I should get a filter for it. I don't know if it's exactly right as it is now but it runs and I am so done with this bike. Thank you so much johnj and GS_in_CO for all your help. Seriously it was really nice to bounce ideas around and in any case, I certainly learned a lot in doing this. Plus I think it runs better than when I got it because of the things I did fix on it. It seems quicker than it used to be.

Thanks again!

[GS_in_CO]

Thank you so much johnj and GS_in_CO for all your help. Seriously it was really nice to bounce ideas around and in any case, I certainly learned a lot in doing this.

Yay!

My father and I have been bouncing ideas off each other for 40 years now as we work on cars and get stuck. Everyone learns too.

The vent clearly serves a purpose and it would be good to not let it see unfiltered air. But if it's a vent- there shouldn't be much air movement in or out.

You'll figure something out.