SC Carb, Help!

-Schotte

• My previous post - SC Zenith carburetor adjustments

Not trying to show off... just trying to get more use out of all that darn typing! (grin) It's a shame to use that post only once.

You know- I never could get much use out of the adjustment on my carb idle screw... it doesn't seem to make any difference.

My tractor needs the load screw about 5 turns out before it works correctly under load. Don't know why- but the standard (book) adjustments just never really worked for me.

Your '49 SC project is looking good! Let me know when the pictures with the decals are posted. When it comes time to paint mine- I'd sure like you to teach me something about HVLP sprayers.

-Schotte

This my first paint job but I did find the Wagner fine coat HVLP turbine system very easy to use. The advantage of the turbine is that it heats the air or that is what they tell me. Very little wasted paint as compared to a non-HVLP. But there in lays a problem. The low air pressure produces almost no bounce off the surface being painted, hence the economy of the paint system, but it is hard to paint behind something like the belt pulley. I have really enjoyed using it.
If you have any more questions let me know.

The decal story is another problem. I'm still waiting on Lyle Wacker to send me the rest of them. I only have a partial set.

Randy

Yes- I rebuilt my carb several, several times. Had to do a LOT of trial and error trimming on the bowl gasket to get the floats to clear at first. They would move fine until I tightened the screws... then the floats would hang.

When I finally got it perfected... I traced the damn thing on paper so I'd never have to figure it out again!

Then I adjusted the float level wrong (by going from the "hanging" position instead of the upside-down position.)

I then had a pinhole in the float.

I've been through this carb many times. The only parts I have not removed are the well vent and the two jets (seats). These parts won't budge, and replacements from Zenith aren't available anyway.

The only thing I've never done which might be affecting my idle is that I've never adjusted the idle screw on the choke butterfly. I just left it the way that it's been for the past 20 years.

I've done lots of trial and error adjusting while brush-hogging... and I'm positive I've got the load screw in the best position (for me). I can't explain it.

-Schotte

F.Y.I.- I'm attaching another archive link for you regarding my experiences with the SC carb.

• My previous post- review of SC carb rebuild kits

Randy

I've got the red fiber washer behind where the load screw body screws into the bowl housing.

I also scrounged around the Home Depot plumbing dept. for the world's tiniest O-rings and have a black rubber O-ring around the needle shaft of the load screw. I makes the needle stay where it's adjusted and is tight enough that no air could get in or gas could get out.

I do not have a gasket between the retainer nut and the needle body housing.

-Schotte

Since the needle works under a vacuum I don't think the o-ring will stop air from entering around the shaft unless it is compressed between the retainer nut and housing. I could be wrong, but if you have a setting of five turns and the idle has no effect I would say you are sucking air somewhere.

Interesting problem.
Randy

• 1949 Case SC