No Alternator in Merc Outboard (1975)??

[vampirefish]

Howdy folks. Just acquired a boat with a 1975 (I think) Mercury Outboard 90hp Thunderbolt inline 6. They said that once I get it up and running that the only thing I need to remember is to fully charge the battery prior to taking it out because there is no alternator. Has anyone ever heard of this?

 

[Laddies]

Re: No Alternator in Merc Outboard (1975)??

It came with one from the factory, some one either don't know what their talking about or someone removed it---Bob

 

[vampirefish]

Re: No Alternator in Merc Outboard (1975)??

That gives me hope for the ability to install one! THANKS SO MUCH! I'm waiting for a repair manual so that I can get started.

 

[vampirefish]

Re: No Alternator in Merc Outboard (1975)??

just found some info online:<br /><br />Kiekhaefer Merc Outboard<br />This model was painted all "Phantom Black." <br />The serial number was on a plate riveted to the swivel bracket above and between the clamp screws. <br />Serial numbers 1766824 thru 1932825 were 1965 models. <br />Merc 900E Short Shaft, Electric Starting with Alternator and Merc 900EL Long Shaft, Electric Starting with Alternator models were produced.<br /><br />So it must be a Merc 900E 1965

 

[andrewkafp]

Re: No Alternator in Merc Outboard (1975)??

1965... thats a different animal.<br /><br /> http://www.oldmercs.com/1965merc900.htm

 

[vampirefish]

Re: No Alternator in Merc Outboard (1975)??

Hmmmm....anyone know if an alternator came stock with these? I would think so...<br /><br />I think the service manual I'm picking up will be the 'wrong' years! I'll have to make an exchange <br /><br />By the way, here's a link to my boat - good pix of the engine too: http://www.vampirefish.com/tahiti.html

 

[Laddies]

Re: No Alternator in Merc Outboard (1975)??

Vampire did you ck by looking up under the flywheel to see if you have a alternator winding in place, if you do and the two yellow wires are still attached ck them for resistance, let us know---Bob

 

[WillyBWright]

Re: No Alternator in Merc Outboard (1975)??

You should have an alternator under your flywheel according to my parts reference. Some leads go to the ignition system. The two yellow ones are for charging the battery. Those attach to a rectifier to convert AC to DC. The rectifiers fail mostly from crossed, corroded, or loose battery connections. Stators fail sometimes too. The insulation is probably pretty rotten, so keep that in mind moving them around.

 

[Bondo]

Re: No Alternator in Merc Outboard (1975)??

If I'm Not Mistaken,........<br /><br />The Little Red box(in your pic.s), with the 2 wires running thru the Green casing are a Big part of your Charging System.........

 

[Motor Boater Bill]

Re: No Alternator in Merc Outboard (1975)??

If you can get the link below to work, it will take you to a parts diagram that includes the recitifier. I think that is the "little red box" in the picture. If it is dead, you can get a full wave bridge rectifier from Radio Shack for about $3.50. <br /><br />http://www.mercruiserparts.com/Show_Pictures3.asp?dnbr=%2038612&ivar=images/MERMAR/38612/11.png&inbr=394&bnbr=7&bdesc=STARTER+MOTOR%2C+STARTER+SOLENOID%2C+RECTIFIER+AND+WIRING+HARN ES

 

[vampirefish]

Re: No Alternator in Merc Outboard (1975)??

Hey, thanks so much everyone! I just found a rebuilt lower end that will fit my engine for only $350 (my kid-brother cracked it on a sand bar). I'm going to see if I can swing that - I want this baby in the water this summer (or spring !!!

 

[vampirefish]

Re: No Alternator in Merc Outboard (1975)??

Quick question on my battery. For now I need to charge my battery to see if I can get this thing started (and then troubleshoot my alternator). I have 2500watt 6hp generator that has a handy 12 volt plug-in (on the generator side) with positive & negative connectors, like a jumper cable, on the other end - so that I can charge a battery! How long do you think it will take to charge her up? It's your standard marine deep cycle battery. THANKS!

 

[vampirefish]

Re: No Alternator in Merc Outboard (1975)??

anyone? I'm gonna try to charge my battery tonight!! any suggestions would be great

 

[Motor Boater Bill]

Re: No Alternator in Merc Outboard (1975)??

I'd suggest you use a battery charger to charge your battery, as chargers have built in circuitry, some even automatically reduce the charge as the battery gets charged up. If you have to do it directly from your generator, I'd suggest you monitor it closely. Is the battery new or old? If it's new, it may be good to go. If old, it may not hold a charge. If you have a meter, check the voltage, charge it for a few minutes, check it again, see how it goes. Batteries are dangerous and can BLOW UP so shut off the generator or turn off the 12 volt juice before connectiing and disconnecting the leads, the spark can set off the hydorgen gas that comes from the battery. Ventilation is important. Be careful, take baby steps, and good luck!

 

[vampirefish]

Re: No Alternator in Merc Outboard (1975)??

WOW, thanks for the advice...didn't realize it could be so dangerous. I charged my RV battery from this generator a while back and it worked fine (of course I didn't let it charge for too long). I don't have a voltmeter so I will be careful!! It's a newer battery (only 2 years old) so I'm planning on about 10 minutes to see if it will turn my engine over.