Fuel way high in the fuel window (1 Viewer)

[JohnJL]

Hi All,
Thanks again in advance for the help.

I am starting up a rebuilt F motor with rebuilt carb, so many variables going on. The motor builds oil pressure, starts right up, but doesnt rev happily, and sounds like it is knocking/dies when idling, though I have only had it running ~60 seconds.

I did a bunch of other diagnostics, but one thats obvious is that it is very rich at idle. It doesnt idle long enough to get warmed up or working on the air mixture and idle screw. I notice the fuel level is very high in the carb window. The first few times it ran the fuel level looked at 3/4 up the window, and the last few times I couldnt spor the fuel level at all until I realized it was all the way at the top, above the window!. The plugs look very rich and smell gassy.

So I may (definately) have a few things I am chasing down, but clearly one of them is getting the fuel level in the bowls right. I am getting very short on patience, and only want to do this once more so I am asking for someone to please check I have this right before I button everything up again.

I am pointing to the middle "tang" on the float with the pen in the pics below. When I move the float up and down I can hear the needle valve 'clicking.' I set the float to the manual setting when I rebuilt the carb but its not in front of me now...

So I suspect I need to adjust the float needle upper float adjustment so it opens earlier (lower in the float range as it rises.) Am I correct that if I want to lower the level in the fuel bowl I should adjust the middle tang I am pointing to downwards in the orientation shown in the pics? It seems to me that the tang should be pushed down (as the carb upper lies now upside down) so the needle opens earlier? I believe I got the FSM measurements right when I set it, and the Haynes and Ludel books refer to the FSM...

Thanks for all the advice and your time responding!

 

[4Cruisers]

Yep, the tang should be bent down a bit more. It's not unusual to have to remove and reinstall the carb top hat more than a few times to get the float level correct - at least it's pretty easy to do.

 

[JohnJL]

Yep, the tang should be bent down a bit more. It's not unusual to have to remove and reinstall the carb top hat more than a few times to get the float level correct - at least it's pretty easy to do.

thanks. I wish it was easier than removing 7 screws, 4 linkages, 2 fuel fittings, choke cable, and 3 vacuum lines...

 

[thebigredrocker]

Yeah the Haynes float height didn't work for me. Don't recall what I ended up setting it at. Just now did a search and found someone mentioned 7.5mm worked and another said 6mm

Measuring float height is kinda like measuring point gap IMO. It's a decent start point, but not the holy grail. Sometimes variations in needle and seat assembly height will vary, and the float itself could be out of spec.

Bottom line: what does the fuel level look like in the sight glass? You're aiming for the dot in the middle of the sight glass.

Readjust as necessary.

Hth

Mark A.