Been working on this 40hp Evinrude until I feel as though we have practically rebuilt the whole thing! It had been sitting for several years and it seemed every time we found one problem, another one would arise. Carbs have been rebuilt, all lines have been replaced, primer bulb replaced, new plugs, new fuel pump...Took the boat to the lake yesterday to test again and it ran GREAT...We ran it for 30-45 min. up the lake and no problems. Stopped for a few minutes then when we started back up it wouldn't run over 4000rpms without surging. It did this before and we thought maybe an air leak somewhere. We since put all new lines and clamps. The funny thing is that it doesn't do this consistantly. It will run fine for awhile, then start the surging again. Would it have something to do with the motor getting warmer? If anyone has ANY suggestions, they would be greatly appreciated. Seems this is the only thing left we can't seem to figure out. Thank you!!!
