Topic: CB500 Has me Cornered.. Not Getting Fuel

[Pfraser1]

Hey guys. I have a 1972 cb500 that is trying to rope a dope me. I have:

cleaned the tank
rebuilt the top end fully
New fuel pet cock
Full carb rebuild
New plugs
New wires
Timing is perfect
Added emergo pods
Rejetted carb mains to 115 from 100

For the life of me, the bike won't rev past 7k at idle and if I try to ride it it dies immediately.

It will ride slightly better at half choke but sputters and dies after 100 yards.

It's fuel starved and I don't know why!!

And recommendations?

- Phil

[Scott S]

 You wouldn't be the first guy who was operating the choke backwards. Are you SURE the choke is off when it's supposed to be?

[Pfraser1]

Down is open. Up is choke on

[scottly]

What do your spark plugs look like? Black and sooty means too much fuel or too little air, and white and dry means too little fuel or too much air.

[Duanob]

...and you've gone the wrong way with your jets. 100 is stock for your bike, and pods require larger jets. The 115s are probably too big, but 105s might do. You need to examine your plugs to determine exactly which jetting changes, and possible needle clip changes are required.

I usually don't respond to POD questions but cal is right: 115 mains are way too big for that motor and carb set up. My guess isn't fuel starved but air starved, even with the PODs. That will take care of your 7000RPM limit anyway. As someone mentioned above check you plugs by doing a plug chop. That will give you an answer on air vs fuel.

[Scott S]

 Other than the mains, did you use the factory Keihin brass? Needles, pilot jets, etc? What clip position are the needles in?