5.0L Bravo III engine losing power (fuel/water sep?) - Maxum Boat Owners Club

jmax · 09-02-2010, 12:55 AM

Hey there, new to the forum. Hoping to get some help on a recent problem with my 2006 3100 SE. I have the 5.0L B3s (non-MPI) and have a problem with the port side engine. Last couple trips out, the port engine has noticeably less power and the boat is slower to get up on plane. Both engines used to redline around 4200 RPM, now the port won't go above 3400.

A mechanic friend suggested it might be the fuel/water separator starving the engine at higher RPMs causing this behavior.

Does this sound right?

Any insight is appreciated. Thanks!

capav8r · 09-02-2010, 01:10 AM

I have also seen the anti siphon valve at the fuel tank cause this problem, too.

seapuppy · 09-02-2010, 04:10 AM

Welcome to the zoo...capav8r makes a good point....so..the thing to do is figure out if your getting full fuel pressure to the carb...if not...then if the filter is bad..replace that...there is also a filter at the attach point of the carb...where the fuel line enters the side of the carb.....
also do a compression check on each cylinder......that will tell you what is going on......

SP

ss3964spd · 09-02-2010, 02:27 PM

Does the temp of the port engine go UP when this happens J?

Dan

jmax · 09-04-2010, 10:12 PM

Quote:

Originally Posted by ss3964spd

Does the temp of the port engine go UP when this happens J?

Dan

No, the temp is consistent with the starboard engine - hovers around 180 at cruising speed.

FYI, I replaced both fuel/water separators today. Doesn't seem to have made any difference. I'm trying to avoid handing it over to the shop if its something simple.

Should I replace the anti-siphon valve as well? Is that pretty easy?