I have just removed all my plugs.
What fun. Yes they are black - was running 145 mains in a 1776. Prolly a little rich Craig tells me.

Here is a picture of 3 of the plugs. I had already cleaned one so I could tell if the new jetting was better- it is

But on No.3 cylinder I have a different plug.
3 of the plugs are Bosch Super 4.
No. 3 cylinder has a Beru ultra - some French thingy.

Is there a reason for this?
I think I will just buy 4 new Bosch ones. Suggestions? Terry.

Woah, never seen those fan-dangled 4 tip plugs before

Get bosch W8AC.

Ta muchly

i use them there 4 prongs things take them out every now and then just to stop thread lock had them in now for 12 months should be ok for another 12 months pricey but good

As Craig says get a set of W8AC in Bosch,you will find less problems,over the years we have seen lots of problems with other plugs such as the thread protruding into the combustion chamber,getting a build up of carbon and bringing the thread with it on removal, wrong heat range causing fouling or burning the electrodes.

Thanks Grumble. Have sourced and installed. I don't want to do that again for at least 1 week. But I guess when we are sorting out the jetting.

the Germans think of everything - except what happens when you install a set of Italian carbies !