Mercury 1400 not maintaining velocity

[Chrisk]

We have a Mercury 1400 140HP late 1970s (1977?) motor on our boat that will reach close to top speed from idle when I open up the throttle, but then falls back to about half speed. I bring it back to idle then I can get it going again, but again it falls back to half speed. The boat sat for two years with full tanks. The tanks were treated and we siphoned some of the gas to inspect it. The gas appears to be fine. We've changed the fuel filter. We're speculating that maybe the carbs need cleaning. Anyone have any suggestions on what else might be causing this? Thanks in advance!

 

[Solittle]

Re: Mercury 1400 not maintaining velocity

Chris - Me thinks you are on the right track with the carb rebuild. I would also put a water seperator in the fuel line if you do not already have one.

 

[merc16]

Re: Mercury 1400 not maintaining velocity

sounds to me like the engine aint getting enough gas the carbshould be the problem you should take it off and clean the gunk out of it.

 

[sony2001]

Re: Mercury 1400 not maintaining velocity

Don't you think you should change, rebuild, the fuel pump? Try it before the carbs.

 

[Chrisk]

Re: Mercury 1400 not maintaining velocity

Thanks for the replies.<br />We cleaned out the carbs with a little carb cleaner and we were off and running!<br /><br />Just in time for the 4th of July weekend too!