Hey Hey,
I replaced the leads and plugs on my st141 yesterday afternoon and it ran great apart from flat spots but thats the carby anyway its back to running on 3 cylinders ran on 4 yesterday. I have swapped the plugs and leads around around and 3 isnt working, Had compression yesterday and was even through all cylinders.
Its firing but when i take the lead off when its running it makes no difference.
So wtf maybe a valve stuck open ?