Motor trouble......

[joshdomingue]

Mercury 25 hp ....... just put it on my boat , runs great until your almost on plane and then the motor lugs out. Throttle down to an idle and it runs fine. I have been told that the carb needs cleaning. Someone else told me it was the power pack (not sure what this is). Any advice or suggestions?

[LaAngler]

Make sure your tank vent isn't closed/fuel line stays primed, fresh gas, clean carbs (try sea foam deep creep also)

[PaulMyers]

Josh, Let me know if you continue to have trouble or if you need help cleaning the carb. I can help with that stuff. If it continues after that then it probably is the power pack. It will be cheaper doing the carb first and it probably needs cleaning anyway, if you are anything like me.

[Gerald]

That problem sounds like the high speed jet is clogged up and needs cleaning.

If the engine has not been run in several months.....it could be the old gas and dirty carb. If the engine has set up for a long time.....the gas will have all evaporated and this leaves a thin film everywhere [looks like onion skin] .......in the fuel lines, tubing, carb etc. These would all need to be cleaned or the carb jets will get clogged again.

Also it could be a bad spark plug......had that on a small engine once. This engine ran fine at idle but just did not run as fast as it should at full throttle.

[LPfishnTIM]

sea foam is da stuff to use I pour it in my tank when the gas is more than two weeks old, I'm always concerned about the effects of two cycle oil mixed with gas and ethanol.

[Ray]

My ex brother in law is a boat mechanic for LDWF. He said that mixed gas is better and last longer than straight gas.
You need to keep your tank full to prevent moisture absorbtion in the tank, but it won't help the varnish build up in the carbs. Mixed gas will not varnish as fast as straight gas.
E-10 sucks, EPA and our elected officials have pushed E-15 thru.
Get ready, the corn growers are now pushing for E-20.

Sea Foam is the greatest thing for carbed outboards that has ever been invented.

[joshdomingue]

All of the fuel lines (except for inside the motor)are brand new. Tank is new,with fresh gas. i pulled the plugs ,they don't look bad, but i'm going to change them anyway.... How do you use sea foam .....spray into the carb ? or put in gas tank?

[PaulMyers]

They make both, 1 for the tank and 1 to spray in the carbs.

[Gerald]

Walmart sell Sea Foam.......I think it was ~ $10 for a can.