What are you using now?
I was advised by Yamaha to use an enzyme based stabilizer rather than Stabul or Heet.
The reason I ask is that I had nothing but trouble here in California when they switched over to E10 fuel.
I think an injector cleaner would go ok with the other additive(s), however I'd call your dealer and ask just to be sure.
I have been using some stuff called Star Tron and Ring Free decarbonizer (Or sometimes Seafoam). Now that I use these additives the troubles went away.
If you don't have a water/fuel seperating filter on your boat you would be well advised to get one and run the ten micron elements in it. If you do a search using "ethanol" you will pull some info that might help. I recall I posted some stuff down on the 150 board a while back too.
Here's a link about the Star Tron and E10 fuel...
http://www.startron.com/stretch.php?sec=4