Vintage and Classic Hondas

Gas Draining from Airbox

_‹ Previous Topic Next Topic _›

Classic

List

Threaded

5 messages Options

nilsthenomad

Gas Draining from Airbox

Yesterday I reseated my airbox to my carbs as I was pretty sure I had a little vacuum leak. Got everything put back together and checked for any leaks with some starter fluid. No leaks, took the bike for a quick 2 mile ride around the block and it ran great. Parked it, and after about 5 mins of sitting in the garage gas was dripping out of one of the drain hoses from the airbox. I though it was maybe just a little condensation at first, but it was gas and it kept dripping pretty rapidly, so I closed the petcock and the drip stopped. Then tried to start the bike up and it wouldn't turn over. Let it sit for a few minutes and it still wouldn't start. I have to assume this has something to so with the vent hoses on the airbox. Does anyone know what I need to do to fix it?

'81 CB750K, '70 C70. As long as the Honda's older than I am, I'm happy...

TOOLS1

Re: Gas Draining from Airbox

Administrator

Your needle valve in one, or more carbs is not sealing. Also your drain hoses on the carbs must be plugged. What is happening is the float bowels are over filling, and when the drain hoses are plugged, the gas will run out the back of the carb into the airbox, then flooding everything.
TOOLS

Life is not about the number of breaths, you take, but the moments that take your breath away.
I don't have an anger problem. I have an idiot problem. Hank Hill
Never confuse education for intelligence.
Happiness is a belt fed weapon.
I just can't imagine what could go wrong.
No fire? No explosions? So whats the point of your story?
Those who are too smart to engage in politics are punished by being governed by those who are dumber. ~Plato
It couldn't be done, but the darn fool didn't know it, and did it anyway.
We all got problems. Ksharp
I like vintage bikes because they take me away from the clutter of technology that I work with everyday and back to a simpler time of mechanical elegance and simplicity.. "ninadm"
Darkwing Duck: The worst part of public transportation is the Public.
"That is awesome shit there" Re-Run
"Fear nothing, attack everything" Eric Berry
" Oh, you read that on the internet? Clearly it IS a massive problem. Of course it CAN’t be normal operation."

1976 CB 750-A X 2
1977 CB 750-A X 4
1977 CB 750-K
1976 CB 750 F
1981 CB 750
1966 Kawasaki SG 250
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
1982 Honda XL 80
South of Eden (Kansas City MO)

Re-run

Re: Gas Draining from Airbox

Administrator

In reply to this post by nilsthenomad

Before you run the bike again, check the oil. Many time fuel will get into the cylinders and by the rings into the oil. It will wash all oil off everything and really do bad things. Change the oil if you find gas.

The ride IS the adventure. The destination is just to get gas!

nilsthenomad

Re: Gas Draining from Airbox

Thanks for the advice guys. I had my carbs completely rebuilt and ultrasonically cleaned less than 100 miles ago, so it sucks to hear I might still have carb problems. I'll pull the bowls tomorrow and see what I can find. Will check the oil too.

'81 CB750K, '70 C70. As long as the Honda's older than I am, I'm happy...

Re-run

Re: Gas Draining from Airbox

Administrator

While I kinda dig ultra sonic cleaning, I feel too many shops do not inspect the final product. Most times a US cleaning is fine but not always and things should be inspected to be sure they are clean.

Course it could just be a float needle(s) that may not be working right. I find the rubber tipped needles work best.

The ride IS the adventure. The destination is just to get gas!