It has happened twice now so I think there is a problem. I removed my fuel pump, AIS, stock breather and a bunch of other stuff when I changed from a Silverado to a bobber. I changed my valve seat and needle valve to the 2.5 mm Suzuki one, 175 main jet. Changed the stock breather to a K&N filter. When I get down close to the 1/4 mark on the fuel gauge my bike will not accelerate past 65 or 70. If I try to speed up past 70 it feels like I am running out of gas and stumbles until I let off the gas. Then it will continue to run 65.

Both times I have stopped pretty soon after it happened and filled up. The bike then runs fine. Checked the mileage today and got 44.4 mpg on a easy 111 mile ride through the country. Do I need to put the fuel pump back on? Anything else happening? Thanks for any help.

I didn't know you could run without the fuel pump. I relocated my fuel pump to under the side cover on the right side below the seat. Think this might be an option? Do you have any other pics of your bike, I'd like to see it better, I love the style.

Did you vent your gas cap?

No, did not vent the cap.

Then you're building negative pressure in the tank. More pics...

I didn't vent the cap but isn't the tank vented? There is a vent tube at the top of the tank under the dash. Isn't that a vent?

The tank vent is not enough (at least for like 99% of the folks who get rid of their fuel pumps) to avoid building enough vacuum to cause a problem. The fuel pump can overcome it, but without a pump its a problem.

There is an article in the tech articles about how to vent the stocker.

Gram

You're working with gravity now so the air has to get in there fast. It doesn't have the pump to help suck air in as it sucks gas out anymore. It gets worse with less gas. Some people have cut a 1/2 inch off the main pickup tube too.

Edit - Yeah. What Gram already said.

I will do the cap vent. Would turning the petcock to reserve help with the gravity push?

I'm a little skeptical regarding the need to vent the cap so I'm interested if that will fix your problem.

I'd believe it's more likely that when fuel is low in the tan, the pressure differential resulting from the fuel levels in the tank and the carb bowl is not large enough, therefore, the flow of fuel is not fast enough to keep the float bowl full.

Doc