Loss of power in 50 HP Merc

[LunkerClassic]

I recently noticed a sudden loss of power in my '82 50HP mercury. It idles fine and retains about 15-20% of power when at full throttle in both forward and reverse. I pulled the plugs and noticed 3 of the 4 had a significant carbon buildup, much of it looking wet. Some of the wires also had slight corrosion on the terminals. I'm very anal about the 50:1 mix and am wondering if this is the likely problem. Do I need a different brand plug or one that burns hotter? Or should I go with less than 50:1 oil? I use NGK BUHW-2 plugs. I'm a building contractor and am handy but admit to being a relative novice with engines. Any input would be appreciated as fishing opener is around the bend.

Thanks,
Aaron

 

[verado7]

Re: Loss of power in 50 HP Merc

either a fuel or igniton problem - squeeze the primer and hold it when it gets firm - look at the carbs for fuel running out and the bulb to go soft - that should get you started . post back

 

[LunkerClassic]

Re: Loss of power in 50 HP Merc

either a fuel or igniton problem - squeeze the primer and hold it when it gets firm - look at the carbs for fuel running out and the bulb to go soft - that should get you started . post back[/QUOTE

I just rebuilt one of the carbs that was leaking. My primer bulb has been leaking under pressure; a pretty steady leak. I'm going to replace it but didn't think it was that main problem. Could that be?

 

[Alumarine]

Re: Loss of power in 50 HP Merc

If the fuel line from the tank leaks fuel out, it can also allow air in.

Might not be your problem, but it isn't helping.