Carb rebuild

[CurreyRob]

Looks like the carb on the ol 420c is in need of a rebuild. I used the machine quite a bit last year (but carb was being a pain then). This spring it's leaking fuel from the air inlet and refuses to startup.

What's the best source for either a rebuilt (if possible) or a kit?

The local NAPA can get a rebuild kit, but it's lookin like I may also need a float (which they couldn't get). Nearest deere dealer is an hour away and dunno if I'd have more luck there than the NAPA.

I'm going to pull it this evening and check condition of float (and how gunked it is). If I could get a decent price on a rebuild, I'd do that but the rebuild kit was cheap enuf so that's probably my best bet? (if the float isn't toast). I'm also not sure yet on the carb model (dunno how widely it could vary) ...

TIA for advice on how to proceeed.

Rob

P.S. forgot some details ... a 1957 420C, 12v convert, (holt blade and PTO winch)

[Lavoy]

Rob,
Carb kits are $20 with new throttle shaft, floats are almost as much or more than the kit, I would have to check to be sure.
Lavoy

[CurreyRob]

I just checked and the float is fine ...

Marvel-Schebler Carburetor not sure of model (saw a "742" stamped on I think) ...

I'll put a kit in it, and give it a cleanup.

Any idea on why gas would leak out (without cranking)? the float needle looked ok (perhaps a little aged, but not cracked and still felt like rubber).

The "load valve seat" looked sorta trashed ...

Also, after the kit is put in, any tips for getting it initally dialed in?

Thanks

Rob

[neil]

my 40 is up draft gravity feed. it would leak all the time once it started

[CCWKen]

This may be a little late but I just finished a carb rebuild on my 420C.

I've noticed there's differences in the carb kits. Some will contain the throttle shaft and some don't. Some will contain the low speed adjuster and some don't. Most contain the shaft seals but vary in material. The kit I got at NAPA contains the low speed adjuster but no throttle shaft. Unless your throttle shaft is badly worn, the new seals do a good job of sealing and maintaining butterfly alignment.

The float is easy to test. I wouldn't get the kit or float until you check the float for leaks. Some can be soldered and fixed if leaking.
To Test Float:
Heat a pan of water until you see vapor beginning to rise. Do Not Boil! Hold the float with a pair of needle nosed pliers and submerge in the water. If the float is leaking, you'll see a stream of bubbles coming from the point of the leak(s). No bubbles means the float is good.

There's a few places that will cause a carb to leak fuel.
1. The float is bad. Leaks, fills with fuel and sinks causing the needle valve to stay open.
2. The needle seat or valve is worn or dirt is blocking the seat.
3. The float level is not set correctly.