Purchased 4 x new NGK Spark plugs and Millers Lead replacement from Merlin Motorsport. Purchased 2 x Cans of Unleaded Petrol. Filled tank and dose of additive. Checked gap of spark plugs (bit tight, but give it a go). Fitted the spark plugs, but left leads off and turned engine over. Then put plug leads on and turned engine over with choke fully out (didn’t check to see if the choke was operating). Engine turned over freely but did not fire. Battery was weak, so ceased attempts. Recharged battery over night. Plan to correct Spark plug gap and re-try. If that fails, will check distributer contacts. Note: Haven’t looked at the distributer yet – so maybe a squirt of WD40 would do the trick! Also note that the temperature was very cold so that doesn’t help. There is a routine to check that a spark is making it to the plugs – worth doing also.