1979 230 OMC Sterndrive bogging down

[donsdandy]

I have a 1979 230hp OMC Sterndrive that runs great for 30-45 minutes. After that it bogs down, sputters, won't run with throttle open at all. When it cools down it runs fine until it gets good and warm again. Have replaced plugs, points, condenser, coil, plug wires, rebuilt carb, cleaned valves. It runs better but still sputters when it gets good and warm. Any input would be appreciated.

Thank you.

 

[SeanMcl]

Re: 1979 230 OMC Sterndrive bogging down

Does the water temp gauge show that the motor is running hot or overheating? If so, one thing to check is your water impeller in the outdrive. It is a rubber part that wears out after a while, and eventually you stop getting any cooling water up to the motor.

 

[donsdandy]

Re: 1979 230 OMC Sterndrive bogging down

Does the water temp gauge show that the motor is running hot or overheating? If so, one thing to check is your water impeller in the outdrive. It is a rubber part that wears out after a while, and eventually you stop getting any cooling water up to the motor.

The temp gauge shows 150 degrees the whole time (after warmed up.) It will run fine for 30-45 minutes after that and then it suddenly bogs down.

I failed to mention we have also replaced the fuel filters. No sign of water in the fuel.

 

[superbenk]

Re: 1979 230 OMC Sterndrive bogging down

I have/had similar problems. Seems to be fuel delivery. Last thing I did that seemed relatively successful was to replace the anti-siphon valve on the gas tank. When they get old, they can gum up and stick causing fuel starvation. Next thing I'll try if it comes up again is to re-seat all my gas fittings with sealant to make sure I'm not getting air introduced somewhere. Rebuilding my carb also helped some as did re-timing & tuning the dwell.

Let us know what you find. You might want to check the Adults Only section for the howtos on fuel delivery checks you can perform.

 

[BIGALF]

Re: 1979 230 OMC Sterndrive bogging down

Start checking the fuel from the begining. The fuel pick up tube might have a screen on the end inside the tank that gets clogged up as you run the engine. This is a quick check and it might be a place to start looking.