Ricebiker
CB750 Member
It's most likely too lean. Removed the airbox and put pods on. Oval chrome cheapos. Ok, Vance and Hines 4 into 1 header pipe with Carpy stainless exhaust tip and baffle (Carpy's, So. Cal exhaust fabricator and bike restorer. World famous locally) May as well be wide open.
With the above situation you would think that this bike is going to be lean. Probably is, but I'm getting this flamed backfire when I run it. Barely runs at that. I'm trying to find out if I can tell if the bike is lean from these conditions, because the more I read online, the more confused I get. Some say a flame always means too rich, but I'm also getting an overflow symptom out of #4 carb. Pissing out of the tube. I lowered the float level a bit and the flaming symtom and runability got worse. All this is pointing to a too lean condition. In my opinion. I think what's happening is, the high float level was actually helping with the runability. Even though the carbs were overflowing. A higher float level enrichens the mix, yes?! So, when I lowered the float level the leaner condition got worse and is causing more flaming action and a worse running condition. I moved up to 110 from 100 on the main jets, and 70 from 68 on the pilots. Anyone had success with bigger jumps, like let's say 100 to 150 on the mains? Any other success stories with similar situations?
80 CB750F
VB42's
Main pilots, #70
Main jets, #110
With the above situation you would think that this bike is going to be lean. Probably is, but I'm getting this flamed backfire when I run it. Barely runs at that. I'm trying to find out if I can tell if the bike is lean from these conditions, because the more I read online, the more confused I get. Some say a flame always means too rich, but I'm also getting an overflow symptom out of #4 carb. Pissing out of the tube. I lowered the float level a bit and the flaming symtom and runability got worse. All this is pointing to a too lean condition. In my opinion. I think what's happening is, the high float level was actually helping with the runability. Even though the carbs were overflowing. A higher float level enrichens the mix, yes?! So, when I lowered the float level the leaner condition got worse and is causing more flaming action and a worse running condition. I moved up to 110 from 100 on the main jets, and 70 from 68 on the pilots. Anyone had success with bigger jumps, like let's say 100 to 150 on the mains? Any other success stories with similar situations?
80 CB750F
VB42's
Main pilots, #70
Main jets, #110