150 yamaha skip

I have a 96 150 it runs good but at idle it acts up. it will idle fine then it will gain about 200 rpms. It is like it gains another cylinder. Then it goes right back to normal. It spits so hard you can fell it in the floor of boat.

[boats.net]

Sounds like it's running lean. Probably needs carbs cleaned and synchronized.

carbs just cleaned. cleaned tank new lines from tank to carbs and pumps. I was told could be air fuel adjustment. What is the right setting for each.

[jb123]

sounds like a bad plug or a dirty carb