Spark Plug Type, oil question 73 85hp Johnson

M

mike1234tampa

Seaman
Joined
Feb 1, 2004
Messages
60
Hello,<br /><br />I have an 1973 85 HP Johnson, the plugs in it now our Autolite, from what I have read Champion is prefered, the spark plus as best as I can describe are flat top(higher compression?), unlike the ones in my 1970 85hp Johnson that were conventional. I recently decarbed and also have read you should change after a decarb (even though they still look new).<br /><br />Not to open a can of worms but has anyone used synthetic oil in a motor of this vintage, and if so have an opinion.<br /><br />As I have stated in previos post, this motor sat since 1986, it is in perfect shape and has given me no problem at all in the 12 times out so far with it, just want to keep it that way
 
D

DJ

Guest
Re: Spark Plug Type, oil question 73 85hp Johnson

You can use either type of plug in that engine with very little, if any, difference in performance. I believe the plug you want is: UL77JC4.<br /><br />The syntheics will not hurt your engine. Some Syn's recommend a 100:1 ratio. That, I would stay away from Mix at 50:1 like you always have.
 
You must log in or register to reply here.
Top