Carb flooding
Posted: 19 Dec 2021 08:10
I was investigating a likely source for a small quantity of water in the front carb (PHBH on a Coguaro) Having eliminated the fuel tank as the source I thought it possible that something had gone down one of the pair of fuel breather pipes which run from small ports and terminate on a frame clip.I did wash the bike off the other day. The pathway is essentially downhill all the way back to the carbs.
I tried simply blocking the ends of the tubes. Immediately the front carb just flooded out.
I swapped floats black and white types ,needles and jet The flooding carried on.You could hear it. Fuel was passing direct to the front cylinder. Queue oil change.
What I cannot figure out is why blocking the fuel vent tubes would cause flooding of one carb.Surely fuel level is governed by the float? The only other thing I can think is the float is rubbing on the bowl? Unblocking the pipes stopped the front carb flooding. The rear carb behaved perfectly. Any ideas? After all the carbs on my Sport do not have these fuel vents.
John
I tried simply blocking the ends of the tubes. Immediately the front carb just flooded out.
I swapped floats black and white types ,needles and jet The flooding carried on.You could hear it. Fuel was passing direct to the front cylinder. Queue oil change.
What I cannot figure out is why blocking the fuel vent tubes would cause flooding of one carb.Surely fuel level is governed by the float? The only other thing I can think is the float is rubbing on the bowl? Unblocking the pipes stopped the front carb flooding. The rear carb behaved perfectly. Any ideas? After all the carbs on my Sport do not have these fuel vents.
John