Topic: No fuel in float bowl

[Big Cobra]

Just got my 74 cb750 running better than it ever has…four into one exhaust, pod filters, 110 mains, 40 slow, etc.  Then today back to running like garbage.  Number two cylinder not firing…checked the float bowl no fuel.  Using a brand new petcock, and have fuel filters inline.  There does not seem to be any obstruction in the fuel line.  I removed jets and cleared with guitar string and this does not seem to be the problem.  There doesn't seem to be a float issue.  I'm assuming something is gummed up somewhere…I'm just so tired of pulling the carbs off over and over again…thought I would check and see if anybody had a suggestion before I go at it again.   

[mystic_1]

If there's no fuel in the float bowl, but the other carbs have fuel, that's probably a float valve issue.  With the float bowl removed, turn on the fuel.  Does it flow?  If not, remove the float and the float needle, does it flow then?  If not, you may have some crap sitting above the float needle seat, pull that out and check for flow.  If all that fails, you'd have to pull the carb rack apart to see if the fuel fitting between the #1 and #2 carbs is obstructed.

You could also maybe blow some compressed air through the #1/#2 delivery pipe to see if anything happens.  If I were going to do this, I'd pull the #1 float bowl and float and needle out, and cap off the #1 carb's needle seat with my finger, then blast air into the line to see if the passages to #2 are clear.

mystic_1