18hp 1959 Evinrude Fastwin Questions

[cclaeys]

Just got this motor, runs fine but being the tinkering person I am I am curious about a couple of things. I have searched and read hundreds of posts over the last couple of days and now have a couple of questions. <br /><br />1) The spark plug that is in this is the J6C, from what I have read it is supposed to be a J4C correct? Could any damage have been done by using the J6C?<br /><br />2) There is a plastic fuel filter inline with the gas hose, I am pretty sure this is not "original", what would the proper replacement be for this?<br /><br />3) Fuel/Oil. I have seen 87 Octane and 24:1 recommended for this motor, I live at altitude and the regular unleaded here is 85 octane, is this equivalent.<br /><br />Thanks for the help.

 

[Chinewalker]

Re: 18hp 1959 Evinrude Fastwin Questions

Hi Chris,<br /> I would definitely spring for the 87 octane - 85 is too low. 24:1 is the right mixture, although the 18s I've had are built well enough to handle a slightly leaner mixture of 32:1 using premium quality oil. The choice and risks are yours.<br /><br /> The original fuel filter shouldhave been mounted on the exhaust cover - an aluminum base with a glass bowl, held onto the cover with one bolt. An inline filter, although not original, won't hurt anything.<br /><br /> I actually prefer the J6Cs in my old Johnrudes - tends to burn a tad hotter and reduce fouling at the 24:1 mixtures. No chance for damage to the motors, as there isn't a huge heat difference between the two plugs.<br /><br /> Enjoy! You've got one of the true all-time classic motors there. They built that motor in several incarnations from about 1953 to 1975 or so, originally starting out at about 20-cubic inches/15hp before bumping up to 22 cubes/18 in 1957. <br /><br />- Scott

 

[cclaeys]

Re: 18hp 1959 Evinrude Fastwin Questions

How about finding the prop nut assembly for this thing? I cant seem to locate one. The one that is on it now is just a stainless nut, arent there some spacers or washers of some kind?

 

[rubenadams34]

Does anyone have part number for this fuel line coupler

 

[cc67]

Does anyone have part number for this fuel line coupler

375788