'72 SU Float Level

[Lone_Star]

Thanks Bruce, I will try that next outing. What about the float levels between the two bowls with different length stand-offs? Set them both the same at 23mm?

[Bruce Palmer]

Yes, there is only one length needle and seat that I know of so bend the tangs to accomodate the difference..... I can't tell you why that was done in the first place nor can I say which went where...... It's out and out bafflement!!

[Lone_Star]

Yes, there is only one length needle and seat that I know of .....

Interesting, I will check the carbs and the rebuild kits I used for them. I am pretty sure there are two different length needle and seats.

Thanks!

Bryan

[Lone_Star]

Well, have been out of town on vacation the last week, so did not get back to the Z yet. I did check the carb kit boxes for the needle/seat assemblies that were removed when I rebuilt them. One measures 13/16 in length, the other measures 3/4 inch in length. The carb kits have different part numbers also with all parts being the same except the needle/seats. I have not made time to pull the tops off the float bowls to check the installed needles, but remember them being the same as in the kits. Also have not driven it recently to try adding a bit of choke when hot to see if that helps.

[jerryh]

Are you still having a problem getting the right level on the carbs? I have fix that has worked for years. Install a boat gas priming bulb (about $5 at car stores) in the gas line supplying the fuel pump. Pump it several times to pressurize the system. You'll have to install clear plastic lines on the drain plugs but you'll get the level and you can record and adjust accordingly. Just leave the bulb installed until you get it running right.

Let me know if you have questions and how you like the suggestion.

[jalexquijano]

On ‎06‎/‎25‎/‎2012 at 11:53 PM, emptech said:

Don't have an answer but am working on the same thing. I have Bruce's dvd, but there seems to be a flaw

in using a gage like he does. I machined a gage, my bowls over-flowed. I ended up machining a barb fitting

that goes in the drain hole (like Bruce sells) and used a plastic tube. I've found it is a "cut and try" process,

when I had the level right, the gap between the rim of the lid and top of the float wasn't anything near the

.55". I just bent things to make the 23mm of fuel level to come out right. Took several times.

I also found that often the float would hang up on the sides of the bowl. I took the over-flow barb off and

inserted a small piece of wire to make sure the float was free and not catching. I couldn't figure why my bending

of the tab wasn't changing the level, the float was sticking on something. Now I keep the four screws loose,

wiggle the lid until I know it is free then tighten the screws.

Finished one carb tonight, will finish the second one tomorrow. I bought new bowl valves from Bruce, but they aren't

the ones like in the video with the balls. I have to wonder if that's why my measurement of the bowl height is different,

did he change valves?

Incidentally, I'm using Tygon F4040 fuel line, gasoline proof. Clear and very flexible.

Jim

I tried adjusting to this .55 inch measure with a piece of Wood that measures such amount. In order to obtain that measure i had to bllow through the gas blow and bend the float forward until the needle pin touches the bottom of the float shutting the valve. The result was poor as the car loses power at 4 to 5k rpm which means that the floats were set wrongly.

Should the gap measure be taken with the float parallel to the float lid, meaning fully straight? Is the .055 inch gap taken from the rim of the float lid or from the bottom of the lid?

 

 

[David F]

Forget measuring the float position relative the bowl lid...it does not work.  Remove the sealing washer from under the needle valve body to give more range of adjustment.  Bend tab until fuel level is 1/16" below top of nozzle set at 2.5 turns down...just like most everyone is telling you to do.  If float hits lid when inverted, that is ok as fuel shut off occurs prior to end of range of motion.  Confirm by blowing through inlet and moving float slowly to ensure fuel shut off actually does occur prior to float hitting lid.

Edited February 28, 2018 by David F