115hp blue band mercury starter motor stays on, please help!!

lesqld

Recruit
Joined
Apr 22, 2013
Messages
2
hey, i have a mercury 115hp blue band mercury straight 6 2-stroke,
the motor will start fine but the starter motor stays on, it is not engaged to the fly wheel but is still cranking.
i disconnected the fuel so as that the motor wont start just to test what the starter is doing and it will crank when you flick key from acc to start but then will remain on when the key is back to acc, i had the motor serviced and the start solenoid replaced but the guy who done it just used a solenoid he had rolling around his ute my query is do they have to be pared or is a solenoid a solenoid, could the solenoid be sticking shut??? please help any thoughts?
 

gm280

Supreme Mariner
Joined
Jun 26, 2011
Messages
14,585
Re: 115hp blue band mercury starter motor stays on, please help!!

First of all welcome to iboats :welcome: great to have you aboard...

To answer your question...YES, it does sound like your solenoid is sticking. Your starter solenoid is merely a high current relay. And there is no other way for your starter to get battery voltage to it unless the solenoid is closed. So I'd be looking for a NEW one and not some used one lying around somebody's tool box. To verify it is a stuck relay/solenoid get a volt meter and see if there is voltage at the small terminal on the solenoid without turning the key. If you have voltage on the small terminal, then you have a key switch or wiring problem from that switch... NO other way to have your starter running... I'm betting on a stuck solenoid myself...let us know what fixed it... :D
 

lesqld

Recruit
Joined
Apr 22, 2013
Messages
2
Re: 115hp blue band mercury starter motor stays on, please help!!

First of all welcome to iboats :welcome: great to have you aboard...

To answer your question...YES, it does sound like your solenoid is sticking. Your starter solenoid is merely a high current relay. And there is no other way for your starter to get battery voltage to it unless the solenoid is closed. So I'd be looking for a NEW one and not some used one lying around somebody's tool box. To verify it is a stuck relay/solenoid get a volt meter and see if there is voltage at the small terminal on the solenoid without turning the key. If you have voltage on the small terminal, then you have a key switch or wiring problem from that switch... NO other way to have your starter running... I'm betting on a stuck solenoid myself...let us know what fixed it... :D

hey mate thanks for your help, ive had a better look and the solenoid is still getting power to it keeping it engaged (the wiring is rotten n had it) i am going to re-wire the engine myself. i just cant figure out when 3 of the wires need power either with the acc or start mode of the switch. the cables are the one to the bottom of the switching box (white cable) and one up from that (red cable) and the red wire to the centre of the rectifier. could you help me with this?
from what i under stand the red wire to the switching box will have constant 12v and from off too acc will switch power to the white of the switching box. and the red to the rectifier should fire with the start ??photo.jpg
 
Top