gasoline leak

rphilli550

Been Around the Block
what are the usual areas on a 1976 Honda CB550 that tend to leak gasoline? i have a spot about the size of a basketball on the concrete every 2 days or so but i cant see it dripping from anywhere. where should i look first?

i already ordered a new tank as i needed a new one anyway but im not sure if its the tank thats leaking. oddly enough every now and then i see a phantom droplet on the top of my tank but i think thats just oil. still...im stumped :-\
 
If the leak has stopped by the time you notice the stain it's may be the carb bowls. Check the gaskets on the bowls... I know mine leaked like crazy when I first bought the bike... turns out the gaskets were gone!

Worth checking out anyway.
 
Where is the spot on the concrete in relation to the bike? Right around the swingarm pivot? Do the drain spigots on your carb bowls have tubes on them, and where do they run?

Do you turn the petcock off everytime you park? Sticky floats can cause fuel to overflow out the carb bowl drains, and if you leave your petcock open and/or if it doesn't seal perfectly when closed, fuel will flow into the bowls and overflow once you've shut the engine down and it's no longer consuming the fuel from the bowls.

Depending on where the bike is parked, the gas could evaporate pretty quickly, leaving a basketball sized (which is pretty darn big) spot of gasoline from a constant drip from a single carb bowl.

Also, do you park the bike with the side stand or centre stand? Leaning to the left might contribute to the problem if bowl #1 or #2 are the problem. Drop the bowls one at a time and check the gaskets and float operation. Check the valves too - with the petcock off, remove a bowl. Hold the float up with your finger, then turn on the petcock a bit with a rag under the carbs to soak up gas. No gas should drip. Lower the float, and at one point the valve will open and gas should flow.

If gas is flowing with the float in the upper position, the valve is stuck open and either needs cleaning (soak in carb cleaner) or replacing. If the float is sticky or stuck in the down position, the valve won't be closed as fuel fills the bowl and the float rises (same as in your toilet tank).
 
actually no i dont turn the petcock off when i park it and i always lean it left on its kickstand as i dont have a center stand. the spot is directly under the bike...as in...right smack in the middle. i'll try those suggestions...im sure its either the carbs or the petcock...maybe i'll get off my arse and sort a few things that i think might be causing a couple problems. thanks fella's
 
locOleoN said:
so did you find the source of the leak?



nope i've been so busy at work i havent had time to even bother looking. I've just been turning my petcock off everytime i get off it. My new tank got here a couple days ago so when i get a spare minute im going to start working on getting that ready for paint.
 
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