p24-1953 Posted June 19, 2010 Report Posted June 19, 2010 i have install my second rebuilt carb and i have noticed that the carb bowl is completly empty after sitting a few hours. what can cause this? Quote
Don Coatney Posted June 19, 2010 Report Posted June 19, 2010 i have install my second rebuilt carb and i have noticed that the carb bowl is completly empty after sitting a few hours. what can cause this? A leak would be my first guess. Quote
claybill Posted June 19, 2010 Report Posted June 19, 2010 (edited) obviously you dont see any gas leaking on the outside.... there is the main jet...the step up valve, and the accelerator pump. are they installed correctly? take the carb off, then the bowl off and look at all thaT STUFF. is the gasket for the bowl a new one and seated properly, or a torn used one..? somehow gas is draining into the engine/manifold through something not shutting off properly, i would say. does it run ok? are plugs wet and dirty? does it start up ok? these are questions i would ask myself..then start looking for the problem. take your original carb and tear it apart and look at stuff!! bill Edited June 19, 2010 by claybill add Quote
p24-1953 Posted June 19, 2010 Author Report Posted June 19, 2010 (edited) thanks, for that deep answer man that was insightfull. the carb before did this also. what could be leaking. i see no sign of a leak on the plug on the bottom of the bowl, no external wetness. could the main main jet in the bottom of the bowl be leaking? how tight is it supposed to be? bill that wasnt directed to you.. now don on the other hand.... Edited June 19, 2010 by p24-1953 Quote
claybill Posted June 19, 2010 Report Posted June 19, 2010 the main jet should be finger tight, then a light wrench tweak... bit that doesnt sound like the problem. do you ahve an electric fuel pump?or stock? look at all the fuel delivery items and narrow it down one by one. there could be a gasket missing someplace. my bowls are near empty too after a few weeks or so sitting....it just seeps into the manifold . if it is happening overnight..there is a problem..if longer....you can live with it.. dont know too much here just troubleshooting at things in the fuel delivery system... Quote
p24-1953 Posted June 19, 2010 Author Report Posted June 19, 2010 bill man you type fast i couldnt even appologize quick enough.. i wasnt trying to be a smart a.... Quote
p24-1953 Posted June 19, 2010 Author Report Posted June 19, 2010 it was drained dry in 3 hours today Quote
Don Coatney Posted June 19, 2010 Report Posted June 19, 2010 i have install my second rebuilt carb and i have noticed that the carb bowl is completly empty after sitting a few hours. what can cause this? thanks, for that deep answer man that was insightfull. the carb before did this also. what could be leaking. i see no sign of a leak on the plug on the bottom of the bowl, no external wetness. could the main main jet in the bottom of the bowl be leaking? how tight is it supposed to be? You are welcome for the deep insightful answer. I thought it was as deep and insightful as your original question. If you do not see any visible wetness or leaks I suspect your problem is evaporation. What are the current weather conditions in Macon, GA? Main jet leaking? I dont think so. The carburetor before did this also? Perhaps this is condition normal for this time of the year in Macon. Quote
p24-1953 Posted June 19, 2010 Author Report Posted June 19, 2010 well today it 89 with a heat index of 94 a slight breeze comming from the north north west at 4mph.. tha last carb had a crack in the bowl near the plug on the bottom and clearly was leaking from there. could i use a gasket making material to seal the threads on the step up valve? i dont think its the accelerator pump because fluid will stay in the accelerator pump but the rest of the car will be dry, even if it has sat a few days, or a few hours. Quote
p24-1953 Posted June 19, 2010 Author Report Posted June 19, 2010 don, cont get testy and start treating me like micheal here.... Quote
claybill Posted June 20, 2010 Report Posted June 20, 2010 gas can evaporate ...when exposed to AIR...HEAT CAN MAKE IT EVAP ALSO. why doesnt everyone have this problem..? just trying to talk it thru....making things clear.. bill Quote
p24-1953 Posted June 20, 2010 Author Report Posted June 20, 2010 that was my first thought also. it was evaporating or boiling out after driving the car when it was hot, but i filled it today and let it sit when the car was cool and it still drained. i cant imagine that gas would evaporate that quickly with the carb lid on it. i disassembled the carb tonight and the only thing i could find was one seal was a little off on the step up valve, so I cut a new one and reassembled. we will see if it is empty tomorrow, or Monday. Quote
jd52cranbrook Posted June 20, 2010 Report Posted June 20, 2010 (edited) Are you sure its empty? my bet is its not,, when full,, you will see no fluid in the bowl, a optical illusion. Opps, sorrry,, I just re read the post above Edited June 20, 2010 by jd52cranbrook Quote
randroid Posted June 20, 2010 Report Posted June 20, 2010 p24-1953, If you pull the top off the bowl you should see two small ball bearings of slightly different size. If either of those is missing or they're in the wrong holes you will have the symptoms you describe. Pure and simple. -Randy Quote
p24-1953 Posted June 20, 2010 Author Report Posted June 20, 2010 they are both there.... but i could have put them in the wrong hole.....i will check that out. can anyone say which one the larger one goes in? Quote
Young Ed Posted June 20, 2010 Report Posted June 20, 2010 The smaller one goes under the accelerator pump. I know cause I got the bigger one stuck in there once. Quote
greg g Posted June 20, 2010 Report Posted June 20, 2010 Pull your dipstick and make sure it doesn't smell like gas. If it does you know where the gas is going. Then maybe we can figure out why. The later 50's cars had a sheetmetal heat shield between the carb and manifold, to keep heat from the exhaust maifold from perculating the gas in the float bowl. Just a simple piece of thin stock a litter wider than the carb bowl. and cut out in the pattern of the base of the carb. You would then need another gasket ie betwee the carb and the shield and the one between the shield and the maifold. The later manifolds featured a much lower casting under the carb to allow for the lower hood lines, so that shield was installed to deal with fuel evap issues. Might be worth fabbing one just for grins and giggles. I cheapie teflon coated cookie pan is the the ticket for a doner piece of sheet metal. Quote
claybill Posted June 20, 2010 Report Posted June 20, 2010 well.....you could take the top off the carb and then run the fuel pump til it fills, and keep track for an hour or so... my bet is that it is going into the engine via the manifold...thru cylinder wall and into the oil pan....thT WAS A GOOD SUGGESTION. some folks are testy , trying to make a point. i dont take that too seriously. i try to think of the other guys needs rather than my own.! we all do as we are. there is good info here.. bill Quote
p24-1953 Posted June 21, 2010 Author Report Posted June 21, 2010 what problems would that cause in the long term? im thinking this is causing my 10mpg problem Quote
claybill Posted June 21, 2010 Report Posted June 21, 2010 i am sure the 10 mpg is linked to the bowl problem...long term would be..how is it getting there, and it isnt supposed to!!! maybe someone will contribute soon... bill Quote
james curl Posted June 21, 2010 Report Posted June 21, 2010 I get 10 in town all the time and am lucky to get over 15 on the highway. Quote
greg g Posted June 21, 2010 Report Posted June 21, 2010 oil is supposed to be used as the lubricant, ot a mix of oil and gas. The more gas the less lubrication. There is also the danger of the gas in the block going boom, though its small. my around town milage with dual carbs ad 4.11's is 17 on this stinky modern gas. Quote
Cpt.Fred Posted June 21, 2010 Report Posted June 21, 2010 (edited) now this is interesting, i never checked if my bowl gets dry that fast, but i will the next time! since i'm having a 10mpg problem here, too, this sounds like a good idea... ed, from what you say i can determine that the size of the 2 metall balls in there is dictated by the places they belong to, so it's hard to mess that up, right? (sorry, i don't quite know how to say this in english) what i mean is, unless i was really careless during reassembly, i couldn't have mixed them up? i really don't want to take the carb apart AGAIN... another thing, p24, did you check your vaccuum advance on the distributer? i was told that this could cause massive fuel consumption, too, if it didn't work properly. i checked mine and it is actually not doing anything, so i'll have to buy a new one. good luck on this, we'll beat it someday! Edited June 21, 2010 by Cpt.Fred poor spelling... Quote
p24-1953 Posted June 21, 2010 Author Report Posted June 21, 2010 i havnt checked the vacuum advance but i know i am pulling a good strong vacuum at the manifold. i'm like you i dont think i messed up the 2 ball's and i hate to dissamble the carb again, but if that solves the problem great. how did you check the distributor? Quote
Cpt.Fred Posted June 21, 2010 Report Posted June 21, 2010 i have a strobe gun for engine timing. i checked timing without the vac line on the carburetor base, revved the engine to see if the centrifugal advance would change the timing , which it did. afterwards i put the vac line on there, tightened it and checked again, this time there wasn't any noticable difference, so the vac advance can't be working correctly. Quote
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