Thread: 1988 20 hp johnson outboard

I have a 1992 service manual for the 9.9 through 30 hp models. It says for the 20hp its 34 +/- 1 degrees. Not sure if a 92 and an 88 are identical motors or not. I know around the late 80's they altered the ignition system and the carb on the 9.9/15 family so may have changed the 20/25 family as well. I'd err on the side of caution until you verified it. Too much advance can be really bad.

Does your 20 even have a way to change the timing advance? On the 9.9/15 models I'm not sure you can even change it mechanically.

Thank you so much for that information,as far as I can see under the flywheel and the starter there is a timing stop that alowws you to adjust it. before I diddle with it I will put a timming lite on it and see if that will change it or not will get it on the water in order to check
it tho,thats why I was asking about Joe Reeves method of setting the wide open throttle method because you dont haqve to have it on the water to adjust it,Some how you pull both plugs and then tie off you throttle plate at wide open throttle by just cranking it,and with your timing lite set the high speed timing.but will have to check it out again thank you

Originally Posted by helpme

Thank you so much for that information,as far as I can see under the flywheel and the starter there is a timing stop that alowws you to adjust it. before I diddle with it I will put a timming lite on it and see if that will change it or not will get it on the water in order to check
it tho,thats why I was asking about Joe Reeves method of setting the wide open throttle method because you dont haqve to have it on the water to adjust it,Some how you pull both plugs and then tie off you throttle plate at wide open throttle by just cranking it,and with your timing lite set the high speed timing.but will have to check it out again thank you

Good luck. Those WOT timing adjustments can be tricky for sure.

Joe knows evinrudes. Thats for sure.