New Spark Plugs

As I've now done nearly 4,000 miles I'm taking the precaution of changing the spark plugs. The service schedule says every 2 years, but I want to upgrade from the standard plugs. Caterham do a set of NGK Iridium plugs that are used in the race engines. 

I picked them up direct from the Dartford factory. Probably my last time there before they move to the new place down the road !

To change the plugs you first need to remove the cover plate. On mine this is held in place with 4 x 10mm nuts. Removing it reveals the ignition leads.

I replaced one at a time, just to be sure, but each cable is a specific length for the cylinder. The lead simply pulls off the head of the plug, and then you need a 16mm spark plug socket on an extension to get down to the plugs themselves. The new plugs need to be torqued very low, between 10 ~ 15 lbft according to the NGK spec. I didn't change the gap spacing. Looking at the old spark plugs they seem to have a very healthy brown-tan colour on the tips, so I'm happy the fuelling is ok.

Did a quick test drive and it definitely seems to be an improvement, with a better pickup on throttle. I'll see how it goes on a long drive this weekend to the Big Picnic !