Skip to main content

Replies sorted oldest to newest

First air the garage out and check for leaks, it doesn't take much of a leak to smell bad. Use a paper towel or brown paper bag and grab all the fuel connections to see it it is wet anywhere. If no leak more than likely it's either the fuel tank vent or fuel going past the carb seat this can be caused by a sticking needle valve or excessive much fuel pressure. Sometimes right after your turn off the ignition you may hear the carb percolate which is fuel pressure .

Last edited by Alan Merklin

Curious on the climate you have your car stored in. If it’s a very hot garage your gas tank will build pressure and vent. If not vented correctly it will push gas through the carbs due to the amount of pressure built up. Of course check for gasoline leaks.  Check all line/ hose connections. At the fuel tank , fuel filter and at the carbs.
All cars I have build , I have performed a pressure leak test on the fuel systems. Gasoline and high external heat values don’t mix well.

Be careful of accumulated gas fumes and spark if parked in a garage.  Some have gas water heaters with a pilot light or spark ignition in their garages.  Do buy and carry a good size fire extinguisher.  Look at the BlazeCut fire suppression system too.  All gaslines (unless AN fittings) should have a good hose clamp on them. In hot weather do not fill gas tank to the top - leave room for expansion.

Last edited by WOLFGANG

Never doubt the effect of gas fumes or what can happen. Years ago, living in Denver, I experienced my first encounter with raking fallen leaves. After hours of raking I filled our "burn barrel" with the slightly damp leaves. At the time leaf burning was allowed and after failing to ignite the leaves I poured some gasoline over them; standing back I tossed a burning book of matches into the barrel.......whoomp the leaves shot out of the barrel like wasps from a fallen nest. Needless to say I had to spent the rest of my day raking slightly charred remnants of what were once leaves.

Gas tank venting: very important.  Normal is to have a valve that lets air in as gas is used.  A problem can arise with this if you store the car with partial fill, so there is air/vapor in the tank and the car cools down, like in winter.  Air goes in.  Then spring comes, and the car warms up.  Air and vapor try to expand, but can't. Pressure builds and can push gas into the carb, past the float valve, down the throat, past an open intake valve and past the rings and into the crankcase.  Can fill the crankcase.  Then you start the engine, and the crankcase is full of liquid, some oil and lots of gas.  This builds enormous pressure in the crank case, and that very thin mixture goes right back up past the rings and/or right up the crank vent which is often routed right into a carb or intake manifold. And then the mixture gets burned into a smoke cloud the likes of which you probably have never seen.  You could ask me how I know this, but I just told you.

Add Reply

Post Content
×
×
×
×
Link copied to your clipboard.
×
×