carb

[Robert Thornton]

Has anyone had trouble with carb draining down after week or so. I have elect fuel pump that is showing 5 lbs of psi when not running. I feel like that is to much It should be 3 psi. Opened carb found float on top and dry pot pushed float down carb filled. I think hi psi is sticking float up truck backfires when letting off of gas so must be flooding. I just don't know why gas is draining out or evaporating. Thanks for you're help RT      PS i am getting a psi regulator so I can adj psi

[Merle Coggins]

I don’t remember the exact spec, but 5 psi is the upper end of it. If the pressure were too high it would hold the float down, not up. The gas in the bowl holds the float up to close the needle valve. The fact that pressure holds in the line when the engine is off confirms that the needle valve is staying closed, as it should. However, when the gas evaporates out of the bowl, as it will since it’s a vented container, the float should drop with the fluid level. If it isn’t doing that than you need to investigate what’s causing it to stick. 

 

As for the backfire when letting off the gas... That usually indicates a too lean condition. 

[torqczar]

 The  float  stuck up is going to stop fuel, ..IE: dry bowl..  take   air cleaner off  look down  carb,   KOEO  ,  is fuel dripping on throttle  plates?..  yes/no,  if no fuel present  fuel pressure OK ..    if yes than you have too much fuel pressure and/or trash in needle and seat...    from your symptoms[?]     the float is stuck up,     just remove  carb. top and  float clip remove float, remove needle and seat  . clean clean clean    I'll bet  the needle  sides are dirty and sticking . clean seat ,I use scrubby pad strip  ,stuff it in and turn with small screw driver ,be careful don't scratch with screwdriver,. reassemble needle ,float and pin...  hold down on float clip with finger and  push on float  over needle and seat, does it move freely up and down.. install carb top .. your ready to go..   hope this makes sense.. todays fuel doesn't age very well..

[Fernando Mendes]

35 minutes ago, torqczar said:

 The  float  stuck up is going to stop fuel, ..IE: dry bowl..  take   air cleaner off  look down  carb,   KOEO  ,  is fuel dripping on throttle  plates?..  yes/no,  if no fuel present  fuel pressure OK ..    if yes than you have too much fuel pressure and/or trash in needle and seat...    from your symptoms[?]     the float is stuck up,     just remove  carb. top and  float clip remove float, remove needle and seat  . clean clean clean    I'll bet  the needle  sides are dirty and sticking . clean seat ,I use scrubby pad strip  ,stuff it in and turn with small screw driver ,be careful don't scratch with screwdriver,. reassemble needle ,float and pin...  hold down on float clip with finger and  push on float  over needle and seat, does it move freely up and down.. install carb top .. your ready to go..   hope this makes sense.. todays fuel doesn't age very well..

 

[Robert Thornton]

Thanks to all I will try these suggestions. I am going to reduce psi of fuel.  The carb is seeping fuel at top, no matter how tight the screws are and a good gasket. Thanks again  Robert T

[torqczar]

13 hours ago, Fernando Mendes said:

 

this way that way   , you can still operate float  with top off .. just had top off  carb. on  truck I recently acquired.  

[Robert Thornton]

Does anyone know where to get a carb float height gage for one barrel

[Jerry Roberts]

On 3/14/2018 at 6:16 PM, Robert Thornton said:

Does anyone know where to get a carb float height gage for one barrel

They usually come with a carb rebuilding kit . I wonder if you can use a straight edge and a correct sized drill bit as a gauge . With todays gas the guys usually set the float a little lower than what is called for in the old books . 

[Jerry Roberts]

On 3/14/2018 at 4:39 PM, Robert Thornton said:

Thanks to all I will try these suggestions. I am going to reduce psi of fuel.  The carb is seeping fuel at top, no matter how tight the screws are and a good gasket. Thanks again  Robert T

Probably your seat isn't shutting off the gas , clean as has been described . 

[Jeff Balazs]

The kits sometimes come with two fuel shut off valves that fit different types of internals on the fuel inlets. Get the wrong one fitted and it will never seat correctly. Also dirt etc...can keep it from seating.

Hth, Jeff