1987 50 Mercury rough idling

[Ricky&Lisa]

My mercury will crank easily, idles and runs rough and will not plane out . It acts like it only running at half speed. I have changed plugs, rebuilt fuel pump and checked gas lines. It had good compression. Any suggestions.<br /><br /><br />Thanks <br />Ricky

 

[WillyBWright]

Re: 1987 50 Mercury rough idling

Could be a dead cylinder. If you run it awhile and check the sparkplugs, you can usually tell if any aren't firing if they're still clean.

 

[Ricky&Lisa]

Re: 1987 50 Mercury rough idling

Took carbs back off and cleaned them and did not see anything wrong. I put them back on still idles rough and will not run wide open. Noticed a little puddle of gas in front of the bottom carb.<br /><br />Ricky