2005 johnson 50hp problems

J50PLSOC serial#o1515248
motor is on a 20ft pontoon
oil pump sensor went out last year had replaced and one of the carbs got rebuilt under warr.
first of this season started surging checked out ...both carbs rebuilt
now wont idle and slowly builds rpm under load in neutral it will rev no problem if you add throttle it will idle any ideas on problem

thanks jason

Re: 2005 johnson 50hp problems

bump for some ideas

Re: 2005 johnson 50hp problems

Was Stabil or SeaFoam used prior to layup? Have you checked the plugs? What do they look like? Are you getting any alarms? An engine running on half its cylinders will rev very freely. Stop doing that. Have you checked your fuel for water. Are you using a portable tank a built-in. If the boat has a built in tank it will have an anti-siphon valve that may be sticky. We can't see your engine so you need to help us help you. Have someone squeeze the primer bulb when the engine is acting up. If it picks up momentarily you have a fuel delivery problem that can be anything from a bad fuel pump, clogged fuel pickup in the tank, restricted fuel line, clogged fuel filter, water in the fuel, improper carburetor idle mixture adjustment, a bad carb rebuild and the list goes on.