[Fullhouse]

Guys, I just put on a spare carb (qjet) while I'm waiting for cliff to take care of my other one. I had taken the air horn off to check for a flooding condition. I notice the bowl was not full. I had taken the fuel line off and rigged a mighty vac can with fuel and a line connected to the carb inlet. I filled the can with gas to it so I could see if the needle and seat were working properly. As I proceeded to blow through the line I could tell that the needle was seating as the float raised to its set height (17/32). I let it sit over night and the fuel is gone,not all, but the float was resting on the bottom of the bowl. What gives?

[engineer]

evaporation

[runningbwdog]

Hi,
If you look at the bottom of the carb, you will see two tubes that come out of the bottom of the bowl. In the ends of these tubes are what appear to be lead balls. Sometimes these seals will leak and allow the fuel bowl to drain. CliffR recommends a marine fuel proof epoxy to seal them up or to drill out the lead, tap the tube and install threaded plugs.
Try putting water in the fuel bowl and see if that leaks out over the same time period. Water will eliminate the evaporation theory.
Check your sparkplugs. If they are black and sooty, then you are getting a too rich mixture in your cylinders.
Hope this helps.
Mike

[Fullhouse]

Would the leak be almost imediate in the discribed place? I have taken the carb off and refilled the bowl. I've got the carb sitting on a box to see if would leak. Let it sit for 10 min. No leak, I will check again in the morning.

[Bill Hanlon]

May not leak at room temperature. The Bendix-Stromberg 2 barrel that came on my '57 GMC truck with factory Pontiac 347 V8 would leak down in 20 minutes if it was hot. When cold it didn't leak at all.

[Fullhouse]

Thanks for the replys. I checked it this morning and no leak,but noticable downward movement of the float. I guess I can chaulk the up as evaporation