Ford 800 running rough and fouling plugs

Fiatmom

Member
I have a Ford 800 and I am having an issue with it running rough and stalling, and fouling the plugs.
I replaced the coil ,plugs and rebuilt the carb last fall. The tractor ran well but the next time I
started it the problems began. I did forget to shut the gas off. The oil now looks dark and thin.
Could this be because of gas in the oil? and would the thin oil run past the rings and foul the plugs?
Thank you for your help
Nick
 
Pull the dip stick and then walk say 20-30 feet from the tractor. Take a lighter and see if you can light the oil on the dipstick. If it lights easy then you need to change the oil. Also what spark plugs are you running?? Now days the best plug you can use is the NGK3112 plugs.
 
Did you perform the Fuel Flow Test first? Any signs of fuel leaking? Remove rubber hose connection fron carb throat to air tube intake. Does carb throat have fuel pooling? On carb rebuild, did you set the float at 1/4? Did you use the newer style Float Needle Valve with the extra clip and if so is it inserted correctly? Did you insert the gasket under needle valve seat? Next, is it 6V or 12V? Either way, is the wiring all correct? If 12V do you have a 12V verified coil? If 12V and using the OEM 6V Coil, do you have the additional external 1-OHM RESISTOR in the coil circuit? Did you rebuild the distributor? If so, did you set points correctly and use a timing light thru the insoection cover set at 5 DEG BTDC? Is the firing order correct - 1,2,4,3 CW? Fouloed plugs can be easily cleaned and reused. Hold plug by the white ceramic insulator. Using your BIC BUTANE cigar lighter or an electric Charcoal/Candle lighter stick, burn off the extra fuel on plug. Take your fine mesh brass wire brush and clean off the carbon. Test plug gap with your feeler gage and reset if needed then insert plugs into engine.

NEW STYLE NEEDLE & FLOAT VALVE NOTE EXTRA CLIP:
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FORD 600 & 800 ELECTRICAL w/TIMIMG:
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SPECS:

Points, STD IGNITION BLUE STREAK #FD-8081X; gap set at .025
Spark Plugs, Champion H10 14mm, use newer H12 or AUTO-LITE 437
Use good spark plug wires and good battery cables.


Tim Daley(MI)
 
Don't have much to add on what others have said, but one more thing to check: Are the plugs fouling with 'dry' carbon/soot (sign of running too rich/cold), or is it a greasy/oily fouling (sign of oil entering combustion chamber)?

If fouling from running too rich, maybe carb isn't quite adjusted right. Some folks on here have talked about new gasoline burning longer, and needing to go to plugs one heat range hotter to prevent fouling (this is also a shade-tree workaround to help plug fouling if oil is slipping by your rings - the higher heat-range plugs will help burn oil off the plugs a little better).

If gas has made its way into the crankcase, it could have thinned out the oil and be bypassing your rings like you said. But, thinking about how the 800 is laid out, I think you'd need one holy heck of a lot of gas bypassing the float to get into the crankcase. Your intake hoses would also have to be absolutely perfectly sealed, in which case gas could 'possibly' fill the carb, up the manifold, into the combustion chamber, back down an open valve or past the rings from the top. I don't see this happening though - or you would have definitely noticed more amiss.
 


You would need a high volume fuel pump to pump gas into the cylinders through an updraft carburetor up through the manifold and into the cylinders. Most likely you got the float adjusted improperly when you rebuilt the carb so that the fuel level is too high and it is running too rich. A quick simple way to check is to take a barbed adapter with 1/8 pipe thread and thread it into the drain plug hole on the bottom of the carb, then put a few inches of clear vinyl tubing onto the barb. With this tube held vertically beside the carb you will see where the level is. It should be around 1/4 inch below the upper/lower interface, but check this measurement.
 
Thanks for the input, the odd thing is it ran well all of the fall with no problems.
We had a hard freeze -7 then things went strange. The rad has the proper fluid so I don't think it froze.
A long story but the exhaust is off but this should not affect the running.
I might try a pressure test on the cylinders to check them. could the coil be bad again?
Last year was the year of tractor hell I don't want a repeat.
 
How long has this been sitting since it ran good? How old is the gas in the tank? Leaving the fuel on if the fuel bowl overfilled it should have leaked on the ground. If it's an updraft carb it would have to fill the intake manifold to ever get near getting into the crankcase. Is the oil over full? Running rich and poorly will make the oil dark and put unburnt fuel in the crankcase.
 
(quoted from post at 11:38:36 01/13/23) Thanks for the input, the odd thing is it ran well all of the fall with no problems.
We had a hard freeze -7 then things went strange. The rad has the proper fluid so I don't think it froze.

Maybe there's water in the fuel that froze.
 
If it has an oil bath air cleaner. Check that it is not full of water causing to choke the engine causing it to run rough and rich.
 
If converted to 12 volts you want a coil that says no external resister needed and if your tractor has a ballast resister remove it
 
Well it is doing it again. I ran it l2 weeks ago and it ran well, this week I started it again backed out of the garage and it ran rough and was hard to drive 10 feet. I pulled the plugs and now they are covered in soot. Is there a trick to seeing in the timing hole? mine is partially blocked so I can not see straight in. I checked point and plug gaps. There is new oil. I am at a loss, I would like to cut the fields and plow this year.
 
Well it is doing it again. I ran it l2 weeks ago and it ran well, this week I started it again backed out of the garage and it ran rough and was hard to drive 10 feet. I pulled the plugs and now they are covered in soot. Is there a trick to seeing in the timing hole? mine is partially blocked so I can not see straight in. I checked point and plug gaps. There is new oil. I am at a loss, I would like to cut the fields and plow this year.
 
(quoted from post at 20:33:02 02/17/23) Well it is doing it again. I ran it l2 weeks ago and it ran well, this week I started it again backed out of the garage and it ran rough and was hard to drive 10 feet. I pulled the plugs and now they are covered in soot. Is there a trick to seeing in the timing hole? mine is partially blocked so I can not see straight in. I checked point and plug gaps. There is new oil. I am at a loss, I would like to cut the fields and plow this year.


I suggest that you forget unlikely things like timing changing, and fluids running up hill and try some suggestions already made.
 
You say you replaced all those ignition parts, & the first response you got was "Now days the best plug you can use is the NGK3112 plugs" from Old. Just because you put in new parts does NOT mean they were good. Points don't line up. Condensers are faulty. And plugs are bad out of the box, fail after just a few hours, or maybe last a little while, then start missing & backfiring.
I've had the same symptoms you describe several times & they were solved w/a set of 3112's.
 
(quoted from post at 15:08:57 02/18/23) You say you replaced all those ignition parts, & the first response you got was "Now days the best plug you can use is the NGK3112 plugs" from Old. Just because you put in new parts does NOT mean they were good. Points don't line up. Condensers are faulty. And plugs are bad out of the box, fail after just a few hours, or maybe last a little while, then start missing & backfiring.
I've had the same symptoms you describe several times & they were solved w/a set of 3112's.
quote]

Thanks Lynn I will try them the problem started again. It ran well; for an hour then started missing. I may have to euthanize it.
Nick[/quote]
 

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