Servicing my 1998 1.6 NB this weekend and intend to change the spark plugs. I can only find a spark plug gap of 1.1mm listed on here, does anyone know the equivalent in Imperial as I’m showing my age and only have old fashioned feeler gauges!
Thanks in advance 
45 thou.
Good luck with this, my very old Champion spark plug gauge only goes up to 0.75mm!
IIRC NGK plugs tend to ship with a suitable gap already set.
Thanks for the advice… its the first time Ive changed spark plugs since the days of Mk1 Escorts and Mk2 Cortinas, so it will be an experience!
You may find that your old spark plug wrench/socket is too big. You need a “10mm” plug wrench for the Mazda.
Air filter and plugs changed, Oil and oil filter, plus handbrake adjuctment next weekend. Air Filter was straightforward, using an OEM part from mx5parts, plugs were simple too after buying a decent long reach 10mm socket (thanks for the tip!)
Old plugs were Densos and due to a vague recent service history I chose to change them (NGK’s) just in case. All four plugs were a good even colour and to be honest, probably fairly recent. The old air filter element was dirty and had done its job well. Total job took less than a hour!
The oil service should be fun, I am replacing the old oil with Mobil Super S semi-sythetic (cars history suggested its run semi-synth before) and a Mazda oil filter.
What is the spark gap for 1999 Mk2 1.8 please? Metric or imperial, either is fine.
1.0 mm - 1.1 mm.
1.0 - 1.1mm as niggle said, I found that 3 of the four plugs supplied by mx5parts were pre-gapped, the fourth only slightly out. A really simple job to change plugs on a '5, but make sure you have a decent, long 10mm plug socket. (thanks for the tip niggle). Also, to access to number 4 plug its easier to remove plug leads 3 and 2 for access. The leads are well numbered so no chance of getting them mixed up :)