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[papasmurf]

sudburys, the small hole in the pipe could be the heart of the problem.

[sudburys]

Thanks pspasmurf,

I've found it to be called the bellow that connects the throttle body to the air filter. Would it make sense that that would affect the plug in such a way?

I've ordered a replacement from our hosts so I guess I'll see in time to come.

[Boxerman]

I cannot see why an air leak between the throttle body and the air filter would make a difference on a fuel injected engine? on a carburetted engine, yes - but not a fuel injected one, the bullet doesn't have a MAF sensor does it?.
Frank

[sudburys]

That's exactly what someone at work has said to me boxerman so unfortunately that would put me back to square one with no idea. (Input sad face)

[Beezabryan]

Just a thought, are the plugs oiling up rather than sooting.

[sudburys]

I'm pretty sure it's sooting up as it doesn't feel it look oily and they clean up well with a blow torch

[sudburys]

^ doesn't look or feel oily

[hagis]

Hi if your spark plug is black with soot and not oil this would indicate a mixture problem - ie to much fuel and not enough air, when did you last change your air cleaner element is this blocked ?.

[Boxerman]

ECU should compensate, unless the lambda sensor has been disconnected.
Frank

[ric]

There's a manifold pressure sensor built into the throttle body.

This detects the air pressure between the throttle body and the inlet valve and will supply a reading to the ECU which along with the data from all the other sensors will provide the correct fuel and ignition settings the ECU has been preprogrammed to supply.

If there is an air leak between the sensor and the inlet valve - and on our bikes there are several places for potential leaks to occur, then unlike an engine fed by a carburettor which will run weak with an air leak, the EFI Enfield engine will run much richer and with retarded ignition as this additional air is seen by the ECU as an engine under heavy load.

Check all the joints in front of the throttle body between it and the cylinder head and also the MAP sensor connector itself (found on the air filter side of the bike) to rule out this a possible cause of your richness.