Re: mercury 80 hp not runnng right
Before wasting your money replacing the coil wire or spark plug wires (they have metal cores and don't need replacing unless you see sparking at night), you'd be better off checking out the carbs and cleaning out the distributor cap.<br /><br />You'll at minimum want to pull the float bowl covers on the carbs and check for debris in the float chambers, also for trash in the float needles. You can also remove the brass plug in the front, bottom of each carb (the main jet plug) and blow compressed air thru. Remove the idle mixture adjusting screws from both carbs and blow air thru the idle passages. If everything seems clean and clear, adjust the float level, renew the float bowl gaskets and reassemble. You can get a "carb packing kit" which is pretty cheap and has the commonly-used gaskets. Much less $$$ than a "rebuild kit" which, 9 times out of 10, is totally unnecessary. If the carbs are really nasty, full of varnish or green corrosion, better off to remove them. But then it likely wouldn't run at all if they were that bad!<br /><br />Set the idle needles at approx 1-3/4 turns CCW from fully seated (turn them clockwise all the way in, lightly seated then back out). This will provide a good initial setting which can be fine-tuned on the water.<br /><br />Re: the dist cap, many times corrosion products & debris will cause erratic spark. Carefully note the orientation of the stainless band which holds the cap in place. Remove the lock-nutted screw and pull the cap down far enough for inspection. Note the center carbon contact and spring. It shouldn't be all gummed up, and should move freely when you depress it.<br /><br />You can blow out any light deposits with compressed air, if the cap looks really nasty inside you can use a spray can of carb cleaner to wash the stuff out. Be sure you've disconnected the main wiring harness from the motor or unhooked the battery before doing this.<br /><br />If you see any obvious cracks in the cap, it should be replaced. It only goes on one way, there's a notch to locate it. Be aware that the spark plug wires and coil wire unscrew from the cap, if you pull them out it'll damage them. The coil wire does pull straight out of the coil, it's a hard pull though.<br /><br />Here's a site with good tuning tips, also if you're getting heavily into you should pick up a Selog Mercury repair manual.<br /><br />
http://www.maxrules.com/fixoldmercindex.html <br /><br />Re: "decoking" or decarbonizing, 2-stroke outboards have a nasty tendency to build up carbon deposits due to the fuel-oil mix, many times a decarbonizing treatment will make them run a lot better. I like to use Seafoam and recommend it heartily.
www.seafoamsales.com You can also search this site and read up about its use. You can use spray-type Seafoam "Deep Creep" thru the carb throats for a direct decarbonization, or put the regular Seafom additive in the fuel and it'll treat everything. I would check the carbs first and once you get everthing squared away, decarbonize as a good preventative treatment. If you can't get Seafoam in your area, OMC sells additives/sprays, as do Merc and Yamaha. Chevron Techron additive and Berryman's B-12 also work well in a pinch.<br /><br />HTH and Good Luck...........ed
