After reading a bit I believe this engine is "sneezing" at idle. I did a tune up on it, replaced the fuel pump and hoses and it starts fine. After I run it for a few minutes when I let it idle it sort of sneezes I guess. You could also call it a miss, or it sounds like someone tossed a rag in the engine. You could also desrcibe it as the engine tring to stop and go the other way for a split second. I could even describe it as a single backfire (muffled by the exhaust being in the water. Does this sound like sneezing. The fix was that the engine is running to lean. This engine has a rich-lean knob on the panel. I'm not sure if it even works. At anything above an idle it runs ok.<br /><br />First I'm working on a '70 9.8 Merc (my first) now it's a '75 Evinrude 15hp. I guess my brother in law has the word out about me fixing boat motors now. One thing for sure these old engines have a lot of life in them!! 
<br /><br />Thanks,<br />Rob
<br /><br />Thanks,<br />Rob