Spark plugs fouling on Massey Ferguson MF 35 petrol gasoline 87mm Standard engine

[LouNY]

If all else fails;

 

[DonRybak]

You mentioned a new cap, rotor and plug wires but what about the condenser???

 

[ROUSTABOUT]

Hi Roustabout,

What are umbrella cup valve stem seals and why would they help?
Thanks

They stop oil from your valve stems from getting to your spark plugs. Oil continually runs off rocker arm tips to lube valves. Stem seals seal off the stems.

 

[FordnMassey]

They stop oil from your valve stems from getting to your spark plugs. Oil continually runs off rocker arm tips to lube valves. Stem seals seal off the stems.

Thank you, I get that now.

 

[FordnMassey]

A hotter plug will help this problem. Also make sure that your mixture setting is not too rich, your ignition timing is correct, and the point dwell is per spec. Does your engine hit the correct coolant temperature during your duty cycle? If it doesn't warm up, that could contribute to the problem.

Hi,

I believe the mixture was rich, as it would start on cool mornings 10C/50F without choke. I adjusted and now need the choke. I don't have a tailpipe sniffer to check for over rich, I just do it by nose, which is challenging with a misfire as there's unburned fuel from the misfires. Certainly can't adjust the mix and resolve the misfire as I tried.
Timing checked and set with a timing light. Haven't done dwell.and not sure I have the device.
Water temp rises to 60C/140F in 5 minutes of light work, so I think that's good.
I'll replace the troublesome leads and then try hotter plugs and I haven't replaced the condenser.

Should probably add, I get fat blue white sparks at a plug removed from the cylinder and earthed so I can watch it.

 

[FordnMassey]

You mentioned a new cap, rotor and plug wires but what about the condenser???

Hi,
Yep, condenser is old, so I'll replace that too.
Thanks

 

[BleedingOrange]

Different spark plugs have different lengths which gets the spark closer to the top of the piston, resulting in a much cleaner burn during combustion. Check to see if the plugs are what was initially called for that particular engine. Some have a couple of different options. Maybe carefully check by measuring to see how much room you have when a piston is a top dead center. You might be able to put a hotter plug in with a longer reach into the combustion area on top of the piston.

 

[LouNY]

A longer reach will usually be a "hotter" plug,
you certainly do NOT want a plug with longer threads.
Threads that go into the combustion chamber are carbon catching glow plugs that will be difficult to remove.

 

[telementry]

A hotter plug will help this problem. Also make sure that your mixture setting is not too rich, your ignition timing is correct, and the point dwell is per spec. Does your engine hit the correct coolant temperature during your duty cycle? If it doesn't warm up, that could contribute to the problem.

Champion N21 is the proper plug for your tractor. I was a massey mechanic for years.

 

[FordnMassey]

Hi Telementry,

Is that for the Standard Motor Co 87mm engine? That's the UK supplied petrol/gasoline motor, not the US Continental motor.

Interestingly, Champion N21 are 2 steps hotter when cross referenced to NGK than my current plugs. I'm thinking this might be the solution.

Thanks

Champion N21 is the proper plug for your tractor. I was a massey mechanic for years.