I have an 89 Johnson VRO 70 hp that keeps stalling at idle. Recent carb kits, plugs, fuel filter, and fuel. Starts good, idles rough and then stalls after a minute or so. Will smoothen out and stay running if given a shot of fuel once in a while with the primer button. Runs good at fuel throttle. What is the next step other than replacing with a four stroke. Joking. Maybe.