Carb question

[Jim in SC]

I've been fighting the carb on my H for some time now - it's original to the tractor (1951). Just finished rebuilding my steering and wanted to take it out for a test drive. Got it started and out of the barn and then it died. Can't get it started again now after trying all afternoon. I believe it's flooding. Any advice on two questions?

1. Is this a "simple" fix - lol, probably answered my own question there! I know it won't be "simple"...

2. If I decide to replace the carb, am I better off getting a professionally rebuilt one, or should I get a new aftermarket? I'm not real confident in my ability to rebuild it, although I did rebuild a '51 model Farmall Cub carb successfully.

Looking for some advice. Thanks.

[Scrivet]

I've been fighting the carb on my H for some time now - it's original to the tractor (1951). Just finished rebuilding my steering and wanted to take it out for a test drive. Got it started and out of the barn and then it died. Can't get it started again now after trying all afternoon. I believe it's flooding. Any advice on two questions?

1. Is this a "simple" fix - lol, probably answered my own question there! I know it won't be "simple"...

2. If I decide to replace the carb, am I better off getting a professionally rebuilt one, or should I get a new aftermarket? I'm not real confident in my ability to rebuild it, although I did rebuild a '51 model Farmall Cub carb successfully.

Looking for some advice. Thanks.

My first bit of advice is to figure out why it won't start before randomly throwing parts at it. My second bit of advice is in my opinion most carbs don't need rebuilt, just cleaned. Rebuild kits are most often sold to those who are grasping at straws for a magical fix, and not doing my first bit of advice.

Running then die to me means something changed and in a hurry. Float needle valve stuck open, or something plugged up and not getting gas. Since you say you think it's flooding I take it that it's getting gas. So that eliminates the gas not being turned on, or something plugging up the sediment bowl screen or carb inlet screen. With repeated cranking and not starting it is possible to get gas dripping from a normally functioning carb. The engine is sucking in gas vapor but not burning it. Gas vapor in the manifold condenses back to liquid gas and runs back down into the carb air side.

Time for basic no start troubleshooting, fuel and fire, in the right amounts at the right time. (since it was recently running and nothing has been done to affect the timing, actual engine timing is not suspect at the moment)
Are you sure you're getting a good strong spark at the plugs?
Are the plugs wet with gas after cranking for a little bit?

And to answer question #1, easier to work on than a Cub carb, no warpage to deal with. I soaked mine in straight simple green for like a week while I brushed and scraped through the caked on grease on the outside every now and then as I walked by. Hosed it off, sprayed it down with carb cleaner, and reassembled with a new gasket and packing. Set the rough adjustments, bolted it on and started it up and then fine tuned it. As for #2, only if you drop it during #1 and break it. Honestly, I think you may have to throw it at the floor for that to happen.

Final thought, I recently had a Cub that hadn't been used for awhile. Started it up and gas was pouring out the air side of the carb. Took the carb off, split it and the pin the float pivots on was corroded (as well as everything in there) and the float wouldn't move. Pop the pin out, a little emery cloth, reassemble, check for float easy movement, reinstall, drive off.

[oldfarmkid]

In case it's not flooding a few suggestions. My 1940 H has what looks like a wing nut at the bottom, left side of the carb. Looks to be a float bowl drain.
When mine would start then quit I would open this drain plug to see if any gas getting to the carb. In my case nothing came out, no gas. Make sure fuel turned on at sediment bowl, check. Unhooked fuel line at carb to see what fuel filter at end of fuel line inside the carb looked like. Mine was a mess.
Cleaned but still no fuel. Found filter/ screens on top of the sediment bowl that screw up into the fuel tank when sediment bowl installed on the tank, missing. This allowed rust/scale to plug fuel entry to sediment bowl. Had to buy new sediment bowl assy. so filter/ screens can now stop crud from tank plugging fuel flow. Then spent about two days removing crud from tank. So, if you have fuel flowing out of float bowl drain then it is time to clean the carb. Since you've worked on a carb before just take your time, get the gov to carb sync correct on installation and you should be fine. But first make sure you have good spark at each spark plug. I hook up a timing light to each plug wire one at a time while cranking to make sure spark is there. If you can find someone to crank while you point the timing light at the timing pointer. If you see the timing line on the crank end even close to the pointer it should be trying to start. Like anything else It could be fuel, carb, ignition or all three. Just test each and follow where it takes you.

Good Luck

[Stanton]

Lots of good advice there. Let us know your results.

[Jim in SC]

Great advice from both, thanks. Unfortunately, and entirely my own fault, I will have to wait until tomorrow to try starting it again. I was so frustrated yesterday that I (who else has ever done this - be honest) left the switch on overnight. Dead, dead battery. It's charging now.

Doesn't mean I can't pull the carb and start on what Stanton suggested though.

[staninlowerAL]

Switch left on, battery dead = points need to be checked for burned/pitted contact surfaces. That's probably where the current flowed to ground.

[Rick Spivey]

Jim,

I'm just over near Lake City. Let me know if this thing continues to fight you, a second set of eyes is often helpful.

[John *.?-!.* cub owner]

If it is flooding you should be getting some black smoke, either when it dies or on restart. If no black smoke I would suspect either a blockage in the fuel line limiting the fuel flow, or rust in the gas tank laying over the inlet, etc. If the fuel tank is completely full a plugged gas cap vent will cause it to die soon. Less gas and more air in tank takes longer.

[Jim in SC]

Well, I got it started this morning! Black smoke, as John said, so it's a fuel flooding issue. It's not a dirty tank or fuel line - I've had both of those off within the past few months and they're fine. I'm going to pull the carb tomorrow and take it apart and clean it, then put new gaskets and seals on it and see what I've got. It'll take a few days to get the basic gasket kit, so it will be the weekend before I can put it back on the tractor. If all is well, I'll run with it. If it's still an issue after trying that, then I have a line on a professionally rebuilt cab from one of the Forum's vendors (Joe B at Retrocrop in Alabama - good guy) that I've bought from before. But I'll give the cleaning a try first. And hello, Rick in Lake City. I'll keep you in mind as well!

[Jim in SC]

I pulled the carb a few days ago, disassembled it and cleaned it. Put new gaskets and a new rubber seal for the fuel adjusting screw on it. Put it back on the tractor and it fired up right away. It still needs some adjustments to the carb, but it seems to be running sweet. That saved me $200+ bucks! Awesome. Thanks to all for the GOOD advice!