In the owners manual 999S 2006 there is written that the possible plugs for the bike are: Champion: RG4HC 8654 RG59V NGK: CR9EK I ordered the NGK CR9EK however the terminals are the threaded type instead of the stud type which the Champion plug has. The top terminal which the coil connects to. NGK CR9EK: Champion RG4HC: How much of an issue is it? Will it work like with the coil on the threaded terminal?
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/123033730200 A garage probably got some old plugs around you could scrounge the terminals.
A bigger problem is going to be screwing your new plugs in. The plugs sit in a tapered well and NGK plugs have the hex flats that the socket grips on, further down the plug body than Champion plugs. This means it is impossible to properly tighten NGK plugs with a normal plug spanner. Luckily, Sealey make a thin walled plug socket that works perfectly. You'd better order one right now.
There seems to also be a NGK CR9EKB NGK CR9EKB: Spec list CR9EK: https://www.ngk.de/nc/en/product-finder/produktfinder/////CR9EK// CR9EKB: https://www.ngk.de/nc/en/product-finder/produktfinder/////CR9EKB// They seem to be the same spec wise only difference seems to be the terminal solid vs threaded. Would it be advisable to get those instead?
The inside of the coil has 1 big contact point in it, under the rubber boot It has a spring which makes contact with the coil with the small part and the big part goes over the stud of the spark plug Which makes me believe that it doesn't really matter which type of spark plug terminal you have since it always makes contact with the spring, whether nipple or stud. Opinions?
