Mercury 75 EFI Doesn't Like to Start

R

RickFish

New member
I have a 2007 19' Angler with a Mercury 75 EFI. The motor runs great and only has about 200 hours, but it doesn't want to start consistently. When I try to start it, I will get a "click" from the starter relay. After several tries, it finally turns over and starts immediately. I have 12.5 volts at both the solenoid and starter, so it's not the batteries. Would a bad EFI card cause this? Any ideas on what else to try?

Thanks

Rick
 
I'm not familiar enough with the merc to be able to say what it is exactly, but I had the exact same problem with a 2009 Yamaha 225 on our previous boat.

I searched the internet for the same symptoms you described and discovered it was a relatively common problem. The starter relay starts to work intermittently. For me I would try to start the boat, and just get a click. I would wait and try again, and after a number of tries it would finally turn over and start.

I ordered the part from SIM Yamaha, replaced it myself and it fixed the issue.

I know that Yamaha made some of the powerheads for Mercury around the mid 2000s but I don't know if it was your year. I would look at that starter relay.
 
Two most common are: starter relay, as above, and corrosion. 12.5 volts with a fully charged battery which should be 12.7 volts is a drop. When you place a load there is just not enough good conductive surface.

Go thru the whole system pull each connection, clean it with a small wire brush, put in a conductive grease and tighten. That is the cheapest --and needs to be done every year or so.

Is the Bendix gear engaging when you get the "click"? That is pulled up as the first stage before the motor rotates. That needs to be kept clean of salt and materials, plus occasionally a light grease application to the shaft.
 
After replacing the solenoid to no avail, the bendix was engaging but not turning the motor over. I bought a replacement starter. It was a different style and an improvement over the original design. Motor started on the first try! Looks like it was a bad starter all along, but now I know a lot more about the entire engine electrical system.
 
I would clean and tighten the battery connections and on OB side terminal block and down stream to the starter just to R/O poor or bad connections
 
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