18 johnson

[blw270]

I just aqiored an old Johnson 18 horse. The model is FD-19D. Can someone tell me the correct oil to gas ratio and the plug and gap info? Also, was told that it runs good except that it does not idle well. What would be the probable cause? Any other info would be appreciated. Thanks in advance.

brian

 

[samo_ott]

Re: 18 johnson

It's a 1965. 50:1 mixing ratio. I have several of the 18's and they're great engines. Was out in my 1960 yesterday.

If it has not been done already it will probably need new coils (under the flywheel). They might intermittingly be grounding out through a crack to cause the rough idle. The other methods would be to install a carb kit (not hard). If you do not know the history of the engine installing a new water pump impeller is a prudent idea. All of the parts are still available (amny on this site) and at a good price. Steve

 

[tashasdaddy]

Re: 18 johnson

this is the basic tune up procedure. there's a little more to the 18 but not much. most tune up parts at laingsoutboards.com http://outboard-boat-motor-repair.c... 5.5 HP 1954-1964 Ignition System Tune-up.htm

 

[blw270]

Re: 18 johnson

btw, it has electric start. Will tune up still be the same??

 

[F_R]

Re: 18 johnson

Yes

 

[blw270]

Re: 18 johnson

what is the spark plug gap and what plug should I use?

 

[perkdp]

Re: 18 johnson

Champipon J6C (or equivalent) at .030 if I recall correctly

 

[tashasdaddy]

Re: 18 johnson

plug is correct, .030 if you plan on a lot of full throttle running. if you plan a lot of slow speed running, trolling open them to .040. if both .035. opening the cuts down on slow speed fouling.