no spark 77 70 hp johnson

[ashion]

I bought this 1977 70 hp johnsonback in May or June, Dude i bought it from said it needed the starter rebuilt but pull started it to prove it worked (no electrical stuff was hooked up). I brought it home and didnt touch it for a month and a half while i was working on the boat it was supposed to go on. I got an ignition for it and wired up everything, didnt bother to check to see if it ran because i was going to pull start. Went down to the river and the fly wheel was locked up, didnt think anything of it. Went back to the house and broke the bolt on top and its spinning fine. Before i went back, i wanted to check to see if it ran and im not getting any spark to my 3 spark plugs. What is the possibility of something going out while sitting there that is now causing my motor not to spark? any suggestions on what I should look at?

 

[oldboat1]

You mean you loosened the bolt on top and the flywheel turned after that? Sounds like you have a broken key on the shaft (flywheel spinning on the shaft without turning motor). Probably have to get clearer about what you mean -- may be saying the electric starter would not turn the flywheel. (would likely mean the starter or starter circuit is a problem -- can't spin the engine while it's under compression.)

Pull the flywheel, and see if the key is intact.

 

[racerone]

Did you use a wiring diagram when you hooked up a starter switch ?-----Did you use an original factory ignition switch?------Or one that looked the same ?-------If the motor locked up while sitting there may be water INSIDE the motor and that is now big trouble !

 

[ashion]

I loosened the bolt and i was able to turn the flywheel. Would a weak starter prevent the motor from starting? I found a wiring diagram, took me 4 days to find it. Any time i try to turn the motor on with the ignition, itll try to turn over, it has good compression but no spark

 

[racerone]

Are you saying you have loosened the flywheel nut and now it turns ??----Did you torque the flywheel nut back up ??---The starter motors are elegantly easy too take apart and inspect, go for it !

 

[dragula]

Had a similar problem but I used an electric start with a battery. Thought it was my starter but turned out that battery crapped out on me. In the meantime I tried to rope start my 1977 70 hp evinrude and it only wanted to make 1/4 turns with the spark plugs in...take the spark plugs out and the flywheel should make full rotations with ease. I suggest the same check the key on the gear shaft but also consider hooking up an electric start cause that’s a hell of a motor to rope start...