is it always on boost mate? i had similar and i already had new leads. we replaced dizzy cap(3 times lol ), plugs, regapped the plugs, Gp A coil and still summat wasnt right. the rotor arm was fucked and was spinning freely on the shaft

since then i moved on to a different splutter which is gettin on my tits. think its a fuel pump issue tho so ive sorted out a new one to get delivered.