How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Jeff G. Your Own Question
Jeff G.
Jeff G., Marine Mechanic
Category: Boat
Satisfied Customers: 4728
Experience:  42 years experience, Certified Master Technician, All Major Outboards, Sterndrives, Hi-Performance
Type Your Boat Question Here...
Jeff G. is online now
A new question is answered every 9 seconds

My 2005 Yamaha 4 stroke 150 HP will not crank. The solenoid

This answer was rated:

My 2005 Yamaha 4 stroke 150 HP will not crank. The solenoid clicks and the starter enggaes but will not "crank" the motor. It is not seized up. I have replaced both batteries, fully charged them, checked cleaned and tightened all battery connections, same at the engine side. I also checkced the battery switch. I checked voltage at starter and it is good. It's like there is not enough amperage? Please help.
I will be happy to assist you. If you have a question or need clarification please post back at any time.
More than likely you will need to have the starter rebuilt or replaced. The brushes and armature may be shot.
Put a voltmeter on the starter solenoid/relay check for 12 volts on the large terminal from the battery cable.
Next put your meter on the large terminal going into the starter.
Crank the engine, if the voltage reads 9.5 volts or greater and the starter cranks slowly, replace the starter. If you get no voltage replace the solenoid. If less than 9.5 check the wiring and connections. See if a battery cable is getting hot while cranking, that is an indication of high resistance.
Post back any questions,
Customer: replied 7 years ago.

When you say put the meter on the large terminal going into the starter is that also on the bottom of the solenoid with a braided covered wire coming off it? I can see three wires on the solenoid. The main positive from the battery, another positive red wire going to somewhere? and the braided wire that appears to go to the starter. Without removing everything I can't trace it any further.


Although a 2005 the motor has low hours, @225. Should a solenoid go bad that quickly? I never had any starting problems. Just went to do a maintenance start after sitting @ 60 days and this problem came up.

Starters can go bad simply from sitting, particularly in humid conditions.
What you are checking is the power going to the solenoid and then the draw of the starter. The third small wire is to activate the solenoid.
You are checking on the two large wires.
Jeff G. and other Boat Specialists are ready to help you
Customer: replied 7 years ago.
I shall accept your answer. Thanks for the help. Some further questions though. From prices I have seen online it appears I might as well replace the entire starter combo unit rather than just the solenoid. Does that seem right? Also, is the replacement something I can do or should a trained technician do it? It appears like you just unscrew the old unit and replace it with the new one. Thanks again.
Customer: replied 7 years ago.

You hae not answered my last question. I accepted and paid but need your reponse to my last question.

I apologize, I never received notice of your question.
As for you replacing your starter, yes that is a very doable job.
Disconnect the battery cables at the battery, unbolt and remove the wires making note of which goes where, unbolt the starter and put the new on in it's place. No shimming or other procedures needed.
You can get a new one at discount at