John Deere H running bad high carbon

[Jim Nauert]

My John Deere H is running poorly, keeps getting high
amounts of carbon on spark plugs. I have had the carb
professionally rebuilt, new wires new condenser in mag,
changed plugs multiple times and checked the timing
multiple times. What else could it be?

 

[Richard G.]

Make sure the air cleaner is not clogged up to start off.

 

[JIM MN]

Get coolant temperture up to 200 degrees.....

 

[Jim Nauert]

I was discing with it so had the temp up, almost didnt make it home because no power.

 

[JIM MN]

Other thoughts; does the tractor burn a lot of oil? And what gas are you using? Ethanol or not? Had the tractor been running OK before all this, now has lost power?

 

[rustred]

what else can it be?... a worn out engine. oil fouled. check the compression. are u monitoring if it uses oil?

 

[Jim Nauert]

It was running so so but was giving off a ton of carbon, doesnt burn any oil.

 

[westga]

I would check the intake air from end to end.
From where it enter to the carb. This will be the cheapest thing to do next. You can make sure the oil levels right in the breather also.

 

[JIM MN]

Must be gas soot foul, does not use oil.. Use 87 octane gas.. Lean out carburetor,too rich.. Spark-plugs- try Auto-Lite 3116 non resistor with your magneto, they are the best or champion D21 or D23. Set plugs at .030.. Spark plug wires, copper centers.. Does magneto put out a hot blue spark.. And once again, when working tractor get coolant temp to 200 degrees plus.. Give these a try..

 

[Jim Nauert]

Thanks, Ill try those plugs. Right now using 386 and those I thought were non resistor but discovered they are a resistor plug. Hopefully its a simple fix

 

[Loosehandle]

Sounds like its running on one cylinder sometimes, double check point gap and strength of spark when warm.

 

[Mark-Ia]

Turn the Load screw in on the carb. Black smoke is too much fuel. Just because it was rebuilt, doesn't mean the rebuilder set the carb to run correctly.

 

[Jim Nauert]

Running quite a bit better, put in some non resistor plugs and discovered one of the tappers was set too tight.

 

[Jim Nauert]

Put a professional rebuild carb on it but still having issues with it breaking up oh heavy load and fast idle

 

[used red MN]

We can only assume you are working with the carb rebuilder and he is directing you on adjusting the carb to try and eliminate this problem? Or in short you know the adjustments they set it at is not necessarily the ideal settings for it on your tractor. Correct timing and a working run advance play a part in this. Have you set the valves?

 

[38 Sears Roebuck]

If all else fails from the other suggestions I would try straight non-ethanol blend gasoline. I know my old engines don't like blended gas. Just my two cents.

 

[Loosehandle]

My John Deere H is running poorly, keeps getting high
amounts of carbon on spark plugs. I have had the carb
professionally rebuilt, new wires new condenser in mag,
changed plugs multiple times and checked the timing
multiple times. What else could it be?

Probably running on one cylinder, possibly weak spark and needs new coil in magneto.