Hello

I have a boat with twin 250hp efi 2stroke year 2000

one of the engines has some weird problems:

Starts OK when cold, but when the engine heats it only works on high rpm. maybe a little missfire or lack of power is noticed sometimes. If i lower the gas it shuts down and wont start until it has cooled down.
On random occasions i can make the engine start by pumping the gas and starting. then it idles very roughly like with only 5 cylinders, and smokes a lot.

Spark plugs are new, no water in filters.
using 98oct gas with mercury premium plus 2stroke oil

could it be the ign coils?

Thanks in advance.

,tuomas
Finland