Don't have owner manual for 70hp Johnson. Need to know idle rpm and wide open rpm. Boat is 1977 Sea Star Hawk. About 1200lbs w\motor, tank and battery. Just restored by the way!
Model # 70EL77s. motor runs fantastic. had it on water today. I run a 19 pitch prop by Piranha. best I ever used. gets on plane quickly, just didn't know right idle speed. replaced all three coils and power pack. big improvement. been boating for 35 years just don't know much about bigger motors.
idle and rpm at WOT have no bearing on what boat the motor is sitting on! the specs will be the same on any boat with said motor. I have an "CE" manual 1988 manul for 60 thru 70 models and it says WOT range is 5000-6000 rpms. Idle in gear is 725 +- 25 rpm
if no one knows the exact specs for your yeat , maybe this will help
Thanks for all the info from everyone! Motor idles at about 950 according to tach. Wide open at exactly 5500. Gotta say, not much of a Johnson fan, but this motor is a gem! Local mechanics and dealers tell me I'd be crazy to sell it. was thinking of newer one. Not now, she's a runner! Can get to 32mph under full load. Boat is a 1977 GTX Sea Star, 15' tri-hull. Would post pics if I knew how on this site! Again, thanks for all the help!
