Logo
FULL SITE MENU

Sudden speed loss

H

hoseman

Contributing Member
"hello all- I have a Mercruise

"hello all- I have a Mercruiser 165hp engine on my boat- The issue I'm having is that when I'm accelerating the boat to top speed, everything is going fine, the boat is responding and running strong (40mph). Then all of a sudden, I start losing speed and it drops to about 30mph at full throttle and the boat isn't running strong anymore. Like it bogs down. Any suggestions?- full pump, full filter?....thanks"
 
"Sounds like a fuel issue.
If

"Sounds like a fuel issue.
If the fuel is fresh and the filters and lines are clean, you could try to T in a pressure guage to the fuel line right at the carb.
You should read 4-5 psig at all load ranges. If it drops off at high throttle, the pump is likely the culprit.
Is there a porous media filter right at the carb inlet? If so, this may be clogged and need to be changed.

Rod"
 
Might also check the fuel tank

Might also check the fuel tank vent line for a kink or clogged. Also tank pickup inlet screen.
Or anti-siphon valve sticking.
Try running it on a separate portable tank - if no problem check all of the above.
 
Back
Top