I just bought a boat with a 1978 Johnson 70horse outboard. I am looking for places to find info on it. Looking for what the compression should be, what size sparkplugs it takes (i have the ones on it but it has 2 different plugs, champ L77 JC4 and QL 77 JC4). I have the seloc manual but it is very general.
Also the motor seams to bogging down and dying on me when accelerated. It idles and starts great. shifts into all gears (with some minor cluncking). When i let the motor idle and then manually accelerate the carbs it also boggs down. i noticed that both set of carb valves do not move. only the 2nd valve (closest to the motor) moves with the throttle. It seems to me there is a linkage missing somewhere. what controls the 1st set of carb valves. when i manually move both sets of carb valves together the motor revs up great and does not bog down. any help would be great? first post but been using you guys as a reference for over a year.
Dan!
Also the motor seams to bogging down and dying on me when accelerated. It idles and starts great. shifts into all gears (with some minor cluncking). When i let the motor idle and then manually accelerate the carbs it also boggs down. i noticed that both set of carb valves do not move. only the 2nd valve (closest to the motor) moves with the throttle. It seems to me there is a linkage missing somewhere. what controls the 1st set of carb valves. when i manually move both sets of carb valves together the motor revs up great and does not bog down. any help would be great? first post but been using you guys as a reference for over a year.
Dan!
