Plug lead problem

[Davidb]

Hi guys,need a bit of help,I have a slight splutter from my mx5 mk 1.ok on idle but driving there's a bit of a misfire.happened to my last mx5. Changed the leads all was fine that time.got a set of hi performance leads they seem a bit fatter also there was oil on plug two.my question is are there two different size plug leads on the mk 1 mines a 1.6 1997 mk 1.car failed nct on drivers shock,they never said anything about problem with splutter.Thanks guys.

[Steve]

There are different widths... but they all should fit.
Oil on your spark plug could just be the cam cover gasket leaking into the plug hole.