Engine surges at higher RPMs

[French]

Hi there

I have a 1995 90 hp 3 cyl 2 stroke mercury. When coming back to the dock the other day my engine started cutting out and going back in when throttling up. I changed the fuel water separator to ensure that there was no water in the engine and this didnt help. Not quite sure what is going on and if it is gummed up carbs, fouled inline fuel filter or a spun prop. Anyone have any ideas on what this could be?

Thanks for all of the help

 

[Laddies]

Re: Engine surges at higher RPMs

You need to find out if your losing spark on one cyl or if the carbs are acting up.

 

[French]

Re: Engine surges at higher RPMs

Here is an update and hope someone can tell me if this is a definite carb problem or if something bigger.

I changed the spark plugs and the in-line fuel filter. Took the boat on a few 1/4 mile runs WOT and boat ran great. Today, took it out ran WOT for about 15 minutes then the engine started bogging down, had to keep throttling back so that I could keep going without the engine bogging down. Finally, able to only go about 7 miles per hour (little above idle speed) since more throttle didnt make the boat go any faster. cant get a mechanic to look at it until Monday.

Got back and checked the inline fuel filter and it looked clean. Lot of vacuum in the fule lines since as you can hear it when changing the fuel water separator.

So i am hoping this is a fuel issue and not a cylinder out or power pack gone bad.

Any help?

Thanks