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882993md

Bending float tab direction - 3 screw SU

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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 by 882993md

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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.

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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.

Screenshot_2018-02-11-18-32-20.png

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.

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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.

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

IMG_1446.jpg

IMG_1447.jpg

IMG_1448.jpg

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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.

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

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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. 

IMG_1446.jpg

IMG_1447.jpg

IMG_1448.jpg

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...

Screenshot_2018-02-11-18-32-20.png

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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.

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

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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 by esmit208
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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.

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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

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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.

20180216_202226.jpg

Edited by jalexquijano

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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.

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Two hours? LOL

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!

DSC01678.JPG

 

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