Bending float tab direction - 3 screw SU

[882993md 11]

Hi:

I am adjusting my floats using the method where the adjustment nut is turned down ten turns. After cranking the engine when I peer down into the hole I see that the fuel is low. If I'm correct I want to bend the tab down to allow more fuel?

Additionally I haven't installed the cork gasket as I don't want to damage my new gaskets from repeated removal and install. How will the gasket (once installed) affect the fuel level? Will it go slightly higher or lower?  My guess is that is will raise the lid and increase the fuel level?

Thank you.

Edited February 11, 2018 by 882993md

[siteunseen 3,448 5 Vehicles]

Get some RTV silicone and stick those gaskets onto the lids, you can take them off and on a lot more without tearing them.

I've always read 2.5 turns couterclockwise on the nozzles will leave the fuel level right under the over flow limit or the cusp of the tubes.

And yes the tang on the float should be parallel with the float top with the hump in the middle.  If it looks like a ramp it's too high. The front and rear should be close to the same height off the float.  The ramp in the middle is what's important.

[siteunseen 3,448 5 Vehicles]

If you can get them looking like this to start off with you'll be way ahead.  If it ramps up like Evel Kinevel's it's out of whack.

The best thing to do is get them opening and closing right side up not upside down like the Just SUs DVD shows.  Those are Grose jets and we get the much more sensitive needle valves.  I fought this for a year before I figured it out. Car runs better than ever now.

[882993md 11]

Thank you I'll give it another try.

[esmit208 88]

Another tidbit about GROSE JETS, in addition to them helping to control things in the float bowl they also act like EMULSION TUBES that are common in triple side draft carbrettors. Since your are in there inspect those to ensure no little particles are inside. When the fuel level drops in the bowl the float drops in unison and then the little ball inside the GROSE JET allows fuel to fill the bowl. As the fuel level rises the metal tab on the float comes down and the little ball begins to restrict fuel flow so the bowls don't leak over. This is the sequence of events but it all happens simultaneously to complete a smooth action. Be patient and remember its not an OFF/ON switch, it is a smooth and consistent progression.

[882993md 11]

It appears I don't have that tang on the end of my tabs and they do go up like ramps. 

[esmit208 88]

That center curved portion is what must be adjusted. You are looking at everything you need with the exception of the swivel mechanism. Don't squeeze the float too tightly. It has a seam and must not be separated or the inside of the float will take on fuel and will not act as a float. Go online and there is something in picture or video form to help you with the process.

[esmit208 88]

Take a look at YOUTUBE. There are several videos that really simplify it.

[siteunseen 3,448 5 Vehicles]

1 hour ago, 882993md said:

It appears I don't have that tang on the end of my tabs and they do go up like ramps. 

Bend that back part by the pin holes that's so high, like a ramp, down even with the front part.  Needle nose on the sides of the ramp and roll your hand back towards the pin holes.  Don't bend it, more of a roll so the pin will ride smoothly.  It should look like a speed bump not a ramp.  Equal on the sides like an upside down bowl.  When you get the tang in shape, fine tuning the .55" shut off point is easy.

You did the exact thing I did!  The newer needle valves will not hold the weight of the float like the older Grose valves where they show to turn them upside down to get that .55" gap.  No way in hell can you do that with the newer needle valves.  They should put a Xerox copy in each rebuild kit telling that.  It took me a year to get mine right!  But man oh man is there a tremendous difference once you get them right.

I'll try and find my old thread and post it in the morning,  on my dumb phone now.  Sorry.

Like this...

[siteunseen 3,448 5 Vehicles]

Oh yeah. They are not connected at the back.  Your's look fine the back needs bent down is all.

[siteunseen 3,448 5 Vehicles]

The metal needs to be parallel with the top of the float too.

Your second picture has the pin end a little low.  Those are tougher than they feel.  Don't go all Hulkamania but you can be pretty forceful bending just go slow.  Now that I think back I may have put a small ball bearing under the ramp and push the high part down and curve around the ball.

[siteunseen 3,448 5 Vehicles]

 

[882993md 11]

Thanks I’m looking for a ball bearing. Hopefully I don’t mangle the tab in my attempt. [fingers crossed]

[esmit208 88]

The little pastic ball is inside the GROSE JET. It either restricts or allows flow and I believe it screws into the lid. Uncross your fingers it makes them easier to use.

Edited February 13, 2018 by esmit208
Additional

[siteunseen 3,448 5 Vehicles]

He's talking about a small ball under the float's tang to bend it down.  It looks like the ramp for Snake River rocket jump just like mine did. Float bowls were way to low of fuel that way, started sputtering going up a mountain. Rolled it backwards perpendicular with the street and let the bowls get full went another half mile and did it again.  Straight home and started to work on them. Now they're perfect, car runs better than ever.

[esmit208 88]

1 hour ago, siteunseen said:

He's talking about a small ball under the float's tang to bend it down.  It looks like the ramp for Snake River rocket jump just like mine did. Float bowls were way to low of fuel that way, started sputtering going up a mountain. Rolled it backwards perpendicular with the street and let the bowls get full went another half mile and did it again.  Straight home and started to work on them. Now they're perfect, car runs better than ever.

Ok

[jalexquijano 94]

On 13/2/2018 at 4:44 PM, siteunseen said:

He's talking about a small ball under the float's tang to bend it down.  It looks like the ramp for Snake River rocket jump just like mine did. Float bowls were way to low of fuel that way, started sputtering going up a mountain. Rolled it backwards perpendicular with the street and let the bowls get full went another half mile and did it again.  Straight home and started to work on them. Now they're perfect, car runs better than ever.

Come man. Its really difficult to get the .55 inch gap from the bottom of the lid to the top of the float without pressing the needle valve stem. Am i doing something wrong. The su carb dvd is for su carbs with gross jets not needle and valve. 2 hours trying to adjust without any success.

Edited February 17, 2018 by jalexquijano

[Stanley 81]

Two hours isn't enough. It can be an all day job unless you're lucky and get them both right the first few tries.  I don't think that method is the most accurate anyway. If your tang adjustment is off by 1/32" it's going to be wrong. Make the smallest possible adjustments and test with sightglass or by seeing fuel levels in the nozzles each time.

[siteunseen 3,448 5 Vehicles]

Two hours? 

Took me two months!  That was after driving it with low float bowls for a year.  Never kept the motor fed properly.  Now it does after three different methods. 

First was eyeballing the float roof to the lid's underside, got in the ballpark.

Second was the clear tube matching the top of the conspicuous square on the side of the float chamber, got on base.

Third and final was using a marked clear glass jar and a fuel pump, scored!

 

[DannDZ 12]

On 2/11/2018 at 7:38 PM, siteunseen said:

The best thing to do is get them opening and closing right side up not upside down like the Just SUs DVD shows.

You are so right. I talked with Bruce at ZTherapy and he specifically told me that NOT UPSIDE DOWN ... regardless of what your version of "Just SUs" you have. (Mine is by the original owner. In VHS with a 1996 date!)

He said, as you do, to hold the lid and float assembly just as it is oriented when installed. That means RIGHT SIDE UP. Blow into the gas line and slowly raise the float. When the flow stops, that's what you need to measure. On/Off. The distance from the top to the top of the float should be 0.55 inches. But, he also said this is not rocket science, close is good enough until you really start fine tuning. (Living in a digital world it kind of hard to think of "good enough" working. At least I do.)

-Dann

[DannDZ 12]

On 2/17/2018 at 11:20 AM, siteunseen said:

Two hours? 

Took me two months!  That was after driving it with low float bowls for a year.  Never kept the motor fed properly.  Now it does after three different methods. 

First was eyeballing the float roof to the lid's underside, got in the ballpark.

Second was the clear tube matching the top of the conspicuous square on the side of the float chamber, got on base.

Third and final was using a marked clear glass jar and a fuel pump, scored!

 

Can you explain this rig?

[siteunseen 3,448 5 Vehicles]

4 hours ago, DannDZ said:

Can you explain this rig?

I will do my best Saturday morning  when I'm back home. It's on my laptop.

 

[siteunseen 3,448 5 Vehicles]

16 hours ago, DannDZ said:

Can you explain this rig?

I did this a year or two ago so things get fuzzy but here goes.

After much reading I took a small glass jar that my floats could move up and down without hitting the sides, made a mark 23mm down from the roof of the float chamber lid.

Then I hooked up a low pressure fuel pump, running out of a gas jug to the float lid bung.  Hooked the pump to a battery and after a few tries I got the float tangs bent just right so the valves shut off at the line.  23mm down from the roof.  It was the dead of winter and I had nothing else to do and after doing this my 240 runs better than ever.  Plenty of fuel where before they were starved.  I found this out going up a steep mountain one day and the car started running so poorly it wouldn't pull anymore.  I was running off the back carb only, 3 cylinders.  I rolled the car backwards and cut the steering wheel so it was perpendicular to the road.  The bowls filled up and I could go about another quarter mile up the mountain.  Took about three or four times to reach the top. 

Here's my setup.  Click on "siteunseen replied to a topic" and you'll see all the pictures.  If you need more info maybe can help, let me know.  Cliff

 

[jalexquijano 94]

This is really time consuming. Isnt the sight glass after setting it to .55 ok?

[240260280 2,157 1 Vehicles]

20mm down is fine too.