Rough Idle Mercruiser 30

"I have posted on here before

"I have posted on here before and I would like to thank you guys for your help. I have a 1995 3.0 mercruiser alpha one lx and it has a rough idle. It runs fine but when at idle it is just a little rough. I first took it out after I bought it( it was the first time out in two years for this boat) and it would cough when trying to start and I would have to drop the throttle in neutral to get it going. Naturally thinking it was the gas, I got some b12 chem cleaner and put it in the gas. It seemed to run better. However I pulled the sparkplugs today and they were all black. Is this a fuel issue or is there something else that needs to be done?

Thanks so much"

"It sounds like your Carb,&#43

"It sounds like your Carb,+ possibly More of the Fuel Systems needs to be Rebuilt,+ Cleaned....."

hi
on most models the engine

hi
on most models the engine will only start in neutral.you could be flooding carb which would cause the blacking of the plugs.is carb mixture set up ok?fuel lines clean?could be the simple contaminated fuel thing which i found out running on low revs.at first i would try fresh fuel from a seperate tank before the costs!if not check the lines if not its your carb
good luck
jon

"Jonathan:

Start with the b

"Jonathan:

Start with the basics; new plugs, clean flame arrestor, new fuel filter, spray some carb. cleaner on the throttle shaft and choke shaft bushings. Allow to dry then give a little squirt of a light oil on the shaft bushings and carb. linkage pivot points. Change the engine oil and filter since the excess fuel may have slipped past the rings into the oil diluting it.

Get 2 cans of SEA FOAM and dump one in the gas tank. Remove the carb. fuel inlet filter screen and use a turkey baster with a 6-10" piece of clear tubing attached to it--go ahead and laugh--fill it with 2-4 oz. of SEA FOAM.

So that you don't damage the float, needle valve or their setting, S L O W L Y squirt it into the carb. bowl thru the fuel inlet. Pump the throttle 4-6 times to get the mixture into the carb. passages. Squirt 2 more oz. into the carb. bowl and replace the filter screen. Dump the balance of the SEA FOAM into the oil. Let the boat sit overnight.

The next day, with a garden hose and muffs attached, pump the throttle 1-2 times before starting it. You may have to give it a little more throttle as it rumbles to life. Let it run at idle until it warms up. When it seems to be running smoothly, back the throttle some to let it idle on its own. After it reaches operating temp., increase the idle to about 1000 RPM and let it cook for about 15 minutes--watch the engine temp.

If it won't idle smoothly after this, get a carb kit and rebuild it."

Thanks guys for your help.

Thanks guys for your help.