Need Info On 65 HP Mercury Outboard

I just bought a 1975 65 HP 650 Thunderbolt Mercury and I just need a little info. I'm new to the boating world so any tips about this motor would be appreciated. First off, does this motor have an alternator or the like and if it has, does it charge the battery when its running? If it does have an alteranor, will it produce enough juice to charge the battery or is it <br />basically self sufficient? The reason I ask is because after starting the motor once or twice and running it for awhile, the battery does have enough power to even turn the motor over. Now I know the battery is not in the best of shape(I don't know how long it has been used, came with the boat,) and I plan to replace it soon, but I just want to know if I have a more<br />complex problem(or any problem at all) or will a new battery clear things up? Once started, this motor runs really well, ( top speed of about 40 MPH) and I have no other problems with it, I just need to know if I have a problem or not? Any ideas would really help.

Re: Need Info On 65 HP Mercury Outboard

Yes the motor is suspose to charge the battery, it has a rectifier. If your battery is running down while running, you definately have a problem. I have the same motor as you, and the best advice that I can give you is to put a tester on it and see if the battery is any good, and to see if it is getting any juice from the motor. Also, check your wiring, these motors as well as all older Mercs are notorious for the wires coroding inside the jacket, as well as being very brittle. Replace wires as necessary. If it turns out to be a bad rectifier, they are relativley inexpensive. I know that I have one for a 1969 65hp Merc, and it would work, but it would not bolt to your motor, because it is a different shape from yours.

Re: Need Info On 65 HP Mercury Outboard

even if rectifier was fried, should get more than<br />2 trips outa a good battery IMHO.<br />rectifier is about $40 (cheap), but spend a few <br />extra & and get a good/reliable battery...<br />god luck,<br />M.Y.