2000 Johnson 35 hp, 3 cyl running problem

[TechMike]

Low hours, well maintained. Key was left on, battery went dead. Put in fresh battery, went fishing. Ran fine 1/2 day. On way back to dock, wot, motor died. Restarted right away, idles fine, gets up to speed and flats right out. Can keep running if throttle is closed right away. Acted like fuel delivery problem. Fuel lines and filter clear. Rebuilt fuel pumps. On test, ran fine at wot about 90 seconds, flats out. Will idle, will not maintain speed above idle. I'm thinking ignition problem. Where do I go next? Thanks.

 

[Captain Jeff]

Re: 2000 Johnson 35 hp, 3 cyl running problem

Could be carburetor or ignition related. Have you pulled the spark plugs out? What do they look like?

Also, does it sound like it is misfiring or running very rough?

If it runs fine at WOT for 90 seconds it is likely a carburator probably the float or clogged hose coming into carb. It sounds as if you are using up the fuel in the bowl during those 90 seconds and the bowl is not refilling with fuel fast enough or barely at all.

Good luck.