I'm in the process of resurrecting a 1955 Evinrude 25hp Aquasonic Big Twin. She was "garaged" about 25 years ago when she quit running (I found the reeds on #2 were rotated out of position). She has just received a good scrubbing, carb was ultra-sonic cleaned & new carb kit,- new: points, plugs, coils, condensers, wires, water pump and L/U oil (old oil looked great).<br />She's got good cold compression (110 in each cylinder) and appears to be in generally good condition.<br /><br />I garbage picked (been siting in the mud in the woods) a '55 Jonny 25 as a parts motor. Looks to be exact same motor,
down to the electric choke, rev-limiter , block, leg, foot etc. The only differences I can find are the cowel and the carb set screws.<br /><br />The Low Speed screw on the Jonny looks like I expect, fairly long and tapered to a fine point. The screw on the Rude is a bit shorter and has a stubby tip and has a much shorter section of threads on the shaft. <br /><br />I've fired up the Rude and am having some troubles getting her to idle. Started with screw at 1 1/2 turns. <br /><br />With the Rude Screw in her, she sneezes a bit (I'll be workin' on this in a few minutes). The sneeze seems to gets worse, the more I open the screw.<br /><br />With the Jonny screw in her, she runs rough (caughs) and fuel leaks out of the low speed air circuit (small hole to the right of the Low Speed screw).<br /><br />Can any of you omc vets offer some insights into:<br />1. The differences between the 2 screws (Johny & Rude)<br />2. Why the fuel leaks when the Jonny screw is used.<br />3. What is your "best guess" as to which would be the more appropriate screw to use?<br /><br />Thanx Guys
