84 merc won't idle

[mercerfisherman]

I own a 1984 50 hp. mercury marine outboard, 4-cylinder. (Purchased last summer, ran fine). Ran fine this summer till last week. I can get it to start ok but it won't idle. Everytime I put it into idle it would stall so I couldn't shift into forward. I noticed that the old spark plugs were totally shot(very little tip) so I replaced them with four new ones. But that didn't seem to help. I examined the new set of plugs after starting and running it and I noticed that the second cylinder had oil around the plug. All others remained clean. Also sounds like it might be missing. Gas/oil too rich? Could I have flooded it so bad that it might take days to dry out? Also, is it possible that wrong size primer bulb could affect proper fuel flow?

 

[andy6374]

Re: 84 merc won't idle

Work your way from the fuel tank to the fuel pump to the carbs. Check for air leaks, poorly vented tank, poor fuel pump, bad primer bulb, clogged fuel line and/or inline fuel filter. If all checks out a carb cleaning will probably be in order.

 

[herbo]

Re: 84 merc won't idle

i have the same motor sounds like you fried your switch box , get a spark tester and start the motor and test for spark at each plug wire the one thats dark is the one thats firing, dont run your motor no plugs sure way to cook a switch box<br />herbo

 

[mercerfisherman]

Re: 84 merc won't idle

Originally posted by andy6374:<br /> Work your way from the fuel tank to the fuel pump to the carbs. Check for air leaks, poorly vented tank, poor fuel pump, bad primer bulb, clogged fuel line and/or inline fuel filter. If all checks out a carb cleaning will probably be in order.

 

[mercerfisherman]

Re: 84 merc won't idle

thanx for the tip. i'll see what I can find.

 

[mercerfisherman]

Re: 84 merc won't idle

Originally posted by mercerfisherman:<br />

Originally posted by andy6374:<br /> Work your way from the fuel tank to the fuel pump to the carbs. Check for air leaks, poorly vented tank, poor fuel pump, bad primer bulb, clogged fuel line and/or inline fuel filter. If all checks out a carb cleaning will probably be in order.

 

[mercerfisherman]

Re: 84 merc won't idle

Originally posted by herbo:<br /> i have the same motor sounds like you fried your switch box , get a spark tester and start the motor and test for spark at each plug wire the one thats dark is the one thats firing, dont run your motor no plugs sure way to cook a switch box<br />herbo

thanx for the advice. I'll see what the machanics say.