boat won't run wide open

[cbyrum]

I have a 35hp Mercury outboard and it will not run wide open.
The carb has been rebuilt and it starts and runs fine. When you open the trottle wide open the speed and sound of the motor remains the same. I noticed that when the motor is running the bulb on the gas line gets soft. Maybe not getting the proper amount of fuel?
runs good until put into gear and then it seems to not throttle up the as fast. it also seems to squirt more water out of the pee hole when not in gear.

 

[TommyA]

Re: boat won't run wide open

Several things to check with that problem. 1st is check the fuel vent. If the bulb is going soft to the point of collapsing then there is a vacuum created that won't allow enough fuel to feed the carbs from the tank. Next thing to check would be fuel filters and finally the fuel pump may need rebuilding. All of these would be fairly inexpensive to perform before you take it to a repair facility.

 

[hkeiner]

Re: boat won't run wide open

You can use a vacuum gauge to test for fuel starvation, which may be caused by a restriction in the fuel line, a failing fuel pump, and such. Using a vacuum gauge is a pretty effective way to start troubleshooting a problem such as yours. The following link contains instructions on how to do this. Other simple tests include swapping to an external fuel tank or squeezing the fuel bulb during engine bog to see what happens.

http://www.marinepartsman.com/Mercury-Marine-service-bulletins/Mercury-Mariner/2001/EN_17.PDF

If the above tests do not show a problem, you might then check the spark during engine bog. Perhaps the spark is failing at higher RPMs.

 

[TommyA]

Re: boat won't run wide open

What is the name of a poster that flies in gets the info they need and never returns to post final results?

 

[cbyrum]

Re: boat won't run wide open

Hey I took the carb off and cleaned it again and checked the fuel pump and the motor is running great. thanks

 

[TommyA]

Re: boat won't run wide open

Glad to hear that all is well.