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Jason, Marine Mechanic
Category: Boat
Satisfied Customers: 15669
Experience:  Degree in Marine Technology. Gas and diesel marine mechanic.
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I keep blowing my starter 40 hp 4 stroke mercury. It will

Customer Question

I keep blowing my starter for my 40 hp 4 stroke mercury. It will engage but not spin motor then it smokes. replaced twice. charged battery and started but after 5 hours off charger the previous scenario took place. Bad battery? HELP!
Submitted: 1 year ago.
Category: Boat
Expert:  Jason replied 1 year ago.

Hello my name is ***** ***** am I speaking with?

It could be a number of things. Do you have a hand held volt meter, and are you able to take voltage mesurements? Can I aslo get the serial number on the engine.

Next, what is the history on this engine, when did the problem start?

Customer: replied 1 year ago.
2 years ago. Blew original starter. Replaced last month and boat started fine. Took to lake and it wouldn't turn the motor. Held key for around 5 seconds and smoke came out. Pull started motor during the trip. One time while on the lake the motor died and I instinctively turned the key and it started. Only time it worked. Just had motor serviced. Oil lower end ETC. Serial # *****
Expert:  Jason replied 1 year ago.

Do you have a volt meter?

Customer: replied 1 year ago.
13.5 volts until I turn the key. Keep in mind the bad starter still installed. Don't want to replace again without troubleshooting rest of system
Expert:  Jason replied 1 year ago.

A battery is only 12.6 volts fully charged, so you can never have more than that. Do you have a battery charger hooked up or something?

Customer: replied 1 year ago.
my bad didn't have my glasses on. 12.5 vdc. no charger on
Expert:  Jason replied 1 year ago.

Did you hook the meter up to the main lug on the starter where the battery cables connects to? If yes, did you have the key held to start when you got that reading?

Customer: replied 1 year ago.
At battery. Are there other components in line with the starter. The starter will engage the motor but not spin the motor
Expert:  Jason replied 1 year ago.

What does the voltage measure at the starter with the key held to start and the starter engaged? It should be lower than 12.5

Expert:  Jason replied 1 year ago.

Hello, just checking in, were you able to double check the voltages?

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