Help with carb float level

[noisyone]

...67 Cub Lo Boy with IH carburetor....

I need some advice. I've been having alot of fuel problems with my 67 Cub Lo Boy. The carburetor is overflowing and leaking out the air intake side. Then it won't start up. I'm pretty confident that the carb and all the small passageways are clear. I've had it apart numerous times and cleaned it.

Where I need advice is how to adjust the float level. I don't know where to measure from so I don't even really know how to do it. I'm attaching pictures of the current level that the float can travel. Can someone tell me the process?

[Glen]

Hi,
I posted some info about how to set the float level at your other post on Mar. 13.
Here is the service manual page below. Turn the parts you show in your pics above upside down, like in the lower right pic in the manual page, and measure using the info in the upper part of the page, for the IH carb. You need a measure with 32nd inch markings. It is 1 13/32 inch from the bottom of the float, to the flat carb surface where the gasket seals.
Bend the metal between the float and the needle and seat to adjust it.
Also check the float drop, like in the manual pic.
Hopefully you put in a new needle and seat.
They originally had a fuel line like in the listing from TM Tractor below.

To adjust the float drop, bend the little metal piece sticking up on the right end of the pic below, from TM Tractor.

http://www.farmallcub.info/manuals/gss- ... 002-09.jpg

http://www.tmtractor.com/new/fl/373fp.htm

[Don McCombs]

Glen alluded to it, but note that the measurement is taken WITHOUT the gasket in place.

[Farmallacres-NJ (retired)]

If setting the (static) level doesn't fix it consider.

Bad needle n' seat or 'dirt' stopping it from closing off.

Floats 'gain weight' with the 'crap' building up on the surface. The actual 'fuel level' will change with the weight of the float. The 'crappy crust' build up and pin holes in the float are things to look at.
Me ... I always polished the crusty floats and tested them for pin holes while the carb is apart. To test for 'leaks' after polishing put the float in the freezer for a few minutes then hold hinge part of the float with a needle nose under warm water in a tall glass.
bubbles = bad
no bubbles = good

[Bob McCarty]

If you have calipers, the float height is 1.4" and the float drop is 1.6" .

Bob

[macec3(TX)]

I used the drawing that glen posted above. My cub starts very fast and no more gas dripping from carb.

Spoke too quick. This afternoon the gas drip started again. Must have a piece of trash causing the needle not to seat.

[indy61]

Too much choke. Mine will flood easily also if I don't push in the choke rod as soon as it fires. Feather it in and out a little till it warms up.

[Matt Kirsch]

Sometimes despite your best efforts, new needle, clean everything, lather-rinse-repeat 7 or 8 times... It still leaks.

I've done it all and my '67 still has a slow drip when it isn't running, if I don't turn off the gas. It has a genuine all-metal needle and seat from TM. Float is set right. Still drips every minute or two when shut down. If left for months, the gas tank ends runs empty.

So, I gave up and shut off the fuel when I'm done running it for the day. This doesn't help on my '53 because the new sediment bowl doesn't shut off 100% either. I just don't leave much gas in that one.

[Don McCombs]

Try sealing the needle cage threads with this product. Use it sparingly, so as not to block the orifice. Make sure you let it fully cure before introducing fuel.

[Farmallacres-NJ (retired)]

As poor as fuel is, I always cut the fuel valve off and ran them full throttle till dry and pulling out the choke at the last second.

I was of the opinion that if you needed to use a mounted tool semi-often it deserved another Cub.

Taking carbs apart every time you needed to use 'that machine'.....well That got old quick.

BTW: did ya check that float weight? If the float sinks some it ain't goin to stop the fuel flow at the needle.
Also: I found the Viton (rubber) tip needles worked better for gravity feed. just an opinion.

[Eugene]

Bench test for source of the leak:

Hose barb to fit carb inlet, clear plastic tubing to match the hose barb, funnel small enough to fit inside the clear plastic tubing and a bottle of rubbing alcohol from the dollar store.

Remove carburetor top, turn and block upside down on bench with hose barb, tubing and funnel attached. Funnel above carburetor, fill with alcohol. Observe needle valve area and remainder of carb top for source of leakage.

[Glen]

Hi,
macec3(TX) If you can't get the carb to quit dripping, and everything is set right, you could have gotten a defective needle and seat that won't seal. Tell the place you bought it that it won't seal, and ask if they will give you another needle and seat.