1992 Johnson 150 problem. Need help.

Guys, my buddies just purchased a 1987 Mako 258 with twin 1992 Johnson 150's. They are having problems with one of the engines and we can't figure out what it is. The symptoms are as follows: you cannot take the one engine past 4000 RPM or it will die. Sometimes the alarms sound but most of the time they don't. Most trips you can run the boat for an hour or so and then the one engine just seems to run out of fuel. The check valve ball seems to still have plenty of fuel in it though and is firm for the most part when the engine stalls. After it stalls it will start right up sometimes but you will not be able to give it any throttle or it will stall out. After 10-15 minutes firing it up and trying to give it gas it will fire up and run fine and run great for the rest of the day. The boat has a single 150 gallon tank with we believe 2 pick-ups for each engine. The port engine runs great, it's just the starboard engine that keeps giving them trouble. They are using the 10 micron Mallory fuel filter/water separator and have brand new ones installed. The fuel lines are kinda old and the ones from the filter outlet to the engines are turning silvery in color. We thought that these lines could be sucking air possibly or have build up on the inside??? We are not sure but I just wanted to see what some of you experts thought the problem might be.

The thing that has us puzzled is that after this problem happens the boat runs perfect for the rest of the day even if you stop and drift for a while and let them cool down. Or if we are on a trolling trip and are shutting one engine down to slow troll baits it will always fire right up and run perfect the rest of the day.

This forum has helped me out many times. Thanks again for all that post on here. I'm looking forward to contributing some information in the future.

Thanks!

Re: 1992 Johnson 150 problem. Need help.

I'd locate an auxillary fuel tank and connect it to the motor that is acting up.
If it still acts up, its not your tank or lines. That way you will know to troubleshoot that motor or the fuel line connected to it!

Re: 1992 Johnson 150 problem. Need help.

Good idea. Has anyone else experienced this kind of problem?