gasoline in crankcase


Douglas Grout
 

Weather permitting, I've been using my prewar to drive into town ( 16 miles round trip...check oil before every trip ).  Early this week, before taking it out, I checked and found the crankcase full of gasoline.  I put the car on the lift, drained the crankcase, and left it raised for a couple of days thinking that if  the float in the carburetor is hung up, fuel will continue to percolate down through the carb, into the crankcase and onto a sheet of white paper placed under the open drain hole.  Two days and not one drip.  Fuel level in the gas tank with the petcock open is unchanged.
For that much gasoline to have gotten into the sump, it would have to be a slow drip over the course of the previous week.  This car has a Tillotson DY 1A carburetor calibrated to 7/8 turn idle and 1 5/8 turn main adjustment.  Surely the answer is right in front of me, I just can't see it.


Richard Williams
 

Carefully check your carb. float bowl for any trash of any kind. It may be just a sticky needle. If the needle does stick it may mean your tank is dirty. intermittent  sticking means you should clean the whole fuel system. good luck. Rich W.


Bruce Derenski
 

I’d check the fuel pump. A hole in the diaphragm can dump raw fuel straight to the crankcase. 


On Jul 16, 2020, at 9:09 PM, Richard Williams via groups.io <rwms_2002@...> wrote:

Carefully check your carb. float bowl for any trash of any kind. It may be just a sticky needle. If the needle does stick it may mean your tank is dirty. intermittent  sticking means you should clean the whole fuel system. good luck. Rich W.


Douglas Grout
 

Thanks Rich and Bruce
Yeah...guess I'm guilty of withholding information on this one.  You guys will remember that these prewars use a gravity fed fuel system so it's easy to peer into the gas tank with a flashlight as it's practically at nose level.  The innards on this one are shiny and squeaky clean....the sediment bowl is likewise clean....and I've even got an aftermarket replaceable fuel filter sandwiched between the sediment bowl and the carb.  The whole plumbing from tank to carburetor barely measures 6".  I had this carburetor apart last summer but didn't have a rebuild kit so I just put it back together, bolted it back in place, and everything seemed to work just fine.  Flipping this carb over when it was off the car and trying to blow air through the inlet....couldn't be done.  Flip it right side up....everything clear.  I have not changed the setting on the float since up till now, it's worked well.  Any other ideas otherwise I'll take the carburetor apart again.  Thanks  Doug

On Thu, Jul 16, 2020 at 11:56 PM Bruce Derenski via groups.io <bruce.derenski=icloud.com@groups.io> wrote:
I’d check the fuel pump. A hole in the diaphragm can dump raw fuel straight to the crankcase. 


On Jul 16, 2020, at 9:09 PM, Richard Williams via groups.io <rwms_2002=yahoo.com@groups.io> wrote:

Carefully check your carb. float bowl for any trash of any kind. It may be just a sticky needle. If the needle does stick it may mean your tank is dirty. intermittent  sticking means you should clean the whole fuel system. good luck. Rich W.