Got my splutters back today after I thought they had gone away. I played around with the ht leads this morning and it got better, but they I also had a few minutes rest so it may have dried out the root cause...
on the way home it only spluttered in low revs but still not right, I will check out the below suggestions tomorrow and maybe take things apart for a clean, what's good to put on ht leads or the like to prevent water ingress as this only happens when it's pouring and at speed - we'll about 40...