JD B running Rich

Poppin John rebuilt my carb exactly 2 years ago. It?s from my John Deere 1946 B. It?s started and has run great until recently. I noticed it smoking a little while Bush-hogging the last few weeks. Also, it became finicky to start. Used to be 3/4 choke and started right away. Now, choke and turn choke off after two turns. Crank some. It tries to start and I give it a quick shot of choke. Now, I can?t get it started.

I just pulled a plug. It is black with soot buildup. Oil bath cleaner is clean and right level.

Can you offer some suggestions on what to look at?

Check Air cleaner inlet for possible mud daubers nests, Also look for good hot spark

Plug went bad, put in new and if you can next one hotter. I had a 46 B along with a 49 B, 38 A, 50 AR and 51 A. New plugs would make run good untill they went bad. Not unusual to get a bad plug right out of the box and Champion were the worst. We ran D21 if I rember correctly for everything including the heavy tillage where some say going to higher heat range will make problems it never did for us. And it solved your problem.

Check float level and maybe turn your load needle in some. Ron MN

Check the spark quality at each plug. Weak spark can mimic fuel problems. Go ahead and replace the plugs, just to say you did.

Take a fuel sample from the carb drain. With the tank valve open, catch the flow in a clean glass. You should get a steady flow, not slow to a drip or stop flowing.

If the flow is insufficient, check the sediment screen, there may be a screen inside the tank, and there may be a screen at the carb inlet fitting.

Look at what was caught, if it is dirty, rust chunks, cloudy with water, the tank is contaminated and needs to come off and be rinsed out. If severely rusty, it may be time for a new tank.

A fresh carb is only as good as the fuel that is supplied. If it's contaminated, the bowl is easily removed and cleaned up. Don't be afraid of it, just work over a clean surface so nothing gets lost.

If you go into it, check the float level, give the float the "shake test" for liquid fuel being inside the float. If there is, it needs to be replaced. Lots of info online for carb specs, float level, how to on Youtube.

The air cleaner, not sure on the JD, but typically the oil bath filters have a mesh filter inside the canister. It is often overlooked, it needs to be periodically cleaned. Some easily come out, others are difficult. But if it's clogged, the air flow will be restricted.

Thank you all for a good checklist. I did change plugs. Already was running hotter Champion D21 plugs for years. Didn't know Champions had problems. Still not starting. Usually, I pull a plug wire and watch the spark, the question is, how hot is enough? Points and condenser are a year old. I have heard about junk condensers from China. How can you tell if you got one? Thanks again, Vince

Try anouther set of a different brand. When we had our problems was when we put new plugs in of the champion in 2 of the Deeres, first day out by noon would hardly go, found the plugs like you describe, cleaned and same thing by night,second day same, third day same. This is when TSC had their own brand. got some for both tractors and never had to touch a plug again for 2 years. Main tractors on the farm, did everything from lite to heavy loads. Easiest and cheapest thing to try.