Re: Mercury 6 h.p.
This should really go in the mercy and mariner forum, they may be able to help more. What year is it? Have you checked compression and spark yet? You can make a simple spark tester if you haven't already per
http://forums.iboats.com/showthread.php?t=213548&highlight=spark+tester. If your merc has a cdi ignition, spark should jump about 7/16" and if it has points, it should jump 1/4" or so. Your compression needs to probably be at least 60 psi, at least that's the case on old Johnson motors that are this small because the displacement is changed a lot with the tester. If it's a newer motor, compression will probably be a little higher. It's possible your plug wires are producing a weak spark too, try putting ohm meter on both ends and checking resistance while wiggling the wires to make sure there's no open circuit.
Once you've verified that, you can move on to carburetion. If it's been more than 3 years since it's had a carb rebuild, that may be in order. The Johnson's have an idle mixture knob on the carb and an idle speed adjustment on the tiller handle. You can increase idle speed to keep it from dying if rpms are under about 800 rpm. But the idle mixture helps to make sure the correct air/fuel mixture is right. You can turn the adjustment knob in to lean it out and get it to idle faster/cleaner. See
http://forums.iboats.com/showthread.php?t=167352. JB/SBN may move this thread to the merc forum.
