65hp merc losing power

[rockytop93]

'75 merc 650 3 cyl. Starts great, idles ok runs up to 5100 wot then cuts back to about 3000 after a few munutes of wot. comp good. 115 all cyls dry. 130 all cyls wet. Carbs have been apart and cleaned. Plugs new. This happens every time i take it out to try it. I know it is losing #1 cyl when this happens as i can pull the plugs and #1 will be dry. Wouldn't this be a fuel problem. Could something be happening in the top carb. Replaced all fuel hoses this am before taking it out to try. What could happen in the carb to cause this. This has been an ongoing problem that has gotten the best of me . can anyone help. After it had sat for a while it will be ok again for a few minutes...... can anyone please help

 

[papasage]

Re: 65hp merc losing power

you may have a coil breaking down . i am having the same probablem . got a new coil coming . 1 has a crack in it . mine is a 70 1974 evinrude . hoping that is the probablem . will know this weakin.

 

[bob proudfoot]

Re: 65hp merc losing power

you may have a coil breaking down . i am having the same probablem . got a new coil coming . 1 has a crack in it . mine is a 70 1974 evinrude . hoping that is the probablem . will know this weakin.

I have a 45 hp 50 classic thats doing the same thing. How do you check a coil pack ? there are four on my motor, one for each plug.