View Full Version : Motor problem need help

04-17-2006, 08:31 PM
I took the boat out ran fine for 15 min. then the motor started to bog down. I gave it more gas and the rpms would drop down. I went back at 5 kts which was about all it would do. Any help out there Thank you

Motor is a 305k marine power

06-11-2006, 10:50 AM
I also have a 305k and it is also hard to start after siting for a couple of days. I think the gas is draining back in to the fuel tank. I am going to try puting a fuel check valve at the gas tank. this should prevent back flow into the tank.

06-19-2006, 08:12 AM

Try changing the filters. And be sure there is only a strainer (coarse filter) before the fuel pump, with a filter (fine mesh) after the fuel pump.


Common boating problem. The heat tends to evaporate the gas in the carb. And, if you have an electric fuel pump. the oil pressure has to come up before the fuel pump operates.


PS: I installed a momentary push button to eliminate the last problem."

09-05-2007, 09:11 PM
It's probably water in the fuel pull your water separator and pour the contents into a glass container if there's water in it you will see it settle to the bottom if so change the separator and go boating

07-20-2009, 07:41 PM
"I have a 1974 with 454 400HP twin engines.
I can start the boat fine, but when the port engine comes up to temp (160-170 degree) it shuts down and will not restart until the temp cools down. If I watch the temp and shut it down when it reaches 160 manually, it will restart with no problem. I need ideas and help."

07-20-2009, 08:43 PM
"Kathleen and Mark...
Its usually easier on all if you start a new topic for every different problem, however...

Are the engines sea water cooled or is it a closed (usually mislabeled fresh water cooling) cooling system. What temp does STBD come up to?

If you don't believe FastJeff, then a quick test.
Shut the fuel valve off when you turn your engine off and leave it. Turn valve back on when you want to start it."

07-21-2009, 01:39 PM
These engines are a closed cooling system and the starboard engine is fine. It runs about 160 degrees as well.

07-21-2009, 02:53 PM
"My best guess as to the problem...
Closed cooling systems run at anywhere from 160 to 190 degrees. Raw water systems run in the 130 to 140 range. There is a temperature switch which shuts down the engine when it overheats.
I believe that the temp shutoff switch installed on your engine is the wrong one, i.e., its the one for raw water cooling setup."