Need help badly on 70 hp johnson coil problem!!!

mickeyred

Cadet
Joined
Feb 22, 2012
Messages
12
Had no power at full throttle found out it was #2 coil, changed it with a 1979 70 hp coil this motor is an 83,(dont know if there is a diffrence) ran great for about 5 min then went back to no power at full speed! Thinking it was bad changed it again with the another coil from the old motor, same thing 5 min then sputtering and no power! are the two coils interchangable,and also my volt meter is running at 16 volts is that high could it be an overcharge,idont know, been spending the last 2 days trying to find out! CAN SOMEONE PLEASE HELP!!!!!!THANK YOU IN ADVANCE!!!! ANY ADVICE WOULD HELP!!!
 

Daviet

Fleet Admiral
Joined
Sep 24, 2008
Messages
8,958
Re: Need help badly on 70 hp johnson coil problem!!!

The part numbers for the coil is different between a 79 and an 83, might want to try the correct coil.
Your engine has a rectifier on it to control the charging system, might want to check the system.
Do you have a manual for your engine, might be a good time to invest in one (factory).
 

mickeyred

Cadet
Joined
Feb 22, 2012
Messages
12
Re: Need help badly on 70 hp johnson coil problem!!!

Thanx again daviet, does the rectifier have anything to do with the coil going bad?
 

mickeyred

Cadet
Joined
Feb 22, 2012
Messages
12
Re: Need help badly on 70 hp johnson coil problem!!!

Also could it be the powerpack going,make it run fine then lose power?Anything to do with the volts? Thanx again pal!
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: Need help badly on 70 hp johnson coil problem!!!

The charging system and the ignition system are seperate. It's normal to see 16 volts on an unregulated system like you have. Possible it's a bad pack but hard to tell with out the proper test equipment.
 
Top