mer 650E 1962, Starter, Stator, Rectifier problem?

[Henchman 28]

Hello, I need some help.

I have been reading through the forums and trying to find as many answers as possible but I still have some questions.

Let me start from the beginning. I bought a 14 footer with a mercury 650E 1962. This boat was completely rebuilt by the previous owner. The motor was completely rebuilt with new fuel lines wiring and so on.

On to what happened, I took the boat out on the lake and it started up just fine and ran great all the way across the lake at full throttle. I turned off the motor and ate some lunch. I tried to restart the motor, the starter engaged, but the motor would not fire up. The wind kicked up and began to blow the boat toward the rocks and I franticly tried and tried to start the motor but ended up draining the battery. I had to jump in to keep my boat from smashing on the rocks. (ouch!) Long story short I got towed back in and took my boat home.
I recharged the battery and tried to start the motor, but only the solenoid would engage. As I was checking the connections my hand brushed up against the rectifier and I got burned.
So I figured my rectifier was fried and read through the forums and found a thread about rectifiers. I found this thread. http://forums.iboats.com/showthread.php?t=252433

Yachtzee posted a response to the topic about how he replaced his rectifier with a bridge rectifier 25 amp 50 PIV from radio shack and it worked fine. So I got the same one and hooked it up. (+ to +, ~ to ~ and - to -.) When I connected the battery, poof, the rectifier turned into charcoal.
Other than the rectifier, none of the wires or connections in the engine where burnt.


My questions are these.

Why would a new rectifier go up in a cloud of smoke?

Did I fry my electrical system?

Did I fry my started?

Did I fry my stator?

Where should I start to get my boat up and running?

P.s. The boat shops around where I live charge $95 an hour and it may take 3 to 4 hours to find out what is wrong with the motor before they can begin to fix it. $95 an hour! OMG!
Sorry if my post is too long.

Thanks

 

[CharlieB]

Re: mer 650E 1962, Starter, Stator, Rectifier problem?

First thing to do is to check battery voltage AND polarity, more than a few times I've run across batteries that have 'reversed' poles. It's rare, but a real pain until you think to check. Again, ensure that your battery cables are correct, not reversed, as that will toast a rectifier in less than a 1/2 a heartbeat .

I need to look into this Radio Shack part mentioned, is it a rectifier assy or individual diodes that you connect into a full-wave rectifier bridge? Polarity/direction of the diodes is critical or they will toast.

 

[Laddies]

Re: mer 650E 1962, Starter, Stator, Rectifier problem?

If it takes a shop 3 to 4 hrs to check out a simple problem, they need new help or are thieves. As far as you trouble it sounds like the rectifier did short. Remove the wires and with a ohm meter ck it I don't know if your engine has a finned rectifier still or a diode. if it's finned it should have a 10 t0 1 ohm advantage towards the battery and none to ground. As far as the started with the red wire off the rectifier charge the battery and see if the engine turns over alright and far as the charging system it don't have any thing to do with the running of the engine it starts the engine thats it.

 

[Yachtzee]

Re: mer 650E 1962, Starter, Stator, Rectifier problem?

I thought that I had psosted a reply to you a day or so ago but I do not see it. The radio shack rectifier is a full wave bridge rated at 50 peak inverse ac input volts and 25 amps under load. I do not think that the merc stator can supply 25 amps AC and my three motors do not make more than 45 volts ac. Motor should not be run unless hooked to a battery as this can lead to a fried recifier in some cases as no load to the charging system can lead to overvoltages at high rpm. A short to ground of the plus terminal might fry the thing, but the stator would need to be able to make enough current to do it reverse polarity may fry it. The battery can produce beau coup amps.
Mixing up a (~) terminal with a (-) terminal can fry one of the 4 diodes in the bridge. To run at full rating the radio shack bridge will benefit from a heat sink, the aluminum bracket that the original plate rectifier mounts on can serve.

Weird possibility, a completely dead lead acid battery can accidentaly be reversed charged to some extent if hooked up to a charger backwards. It will usually not charge to a full 12 volts but would still be enough to fry the rectifier.

 

[Henchman 28]

Re: mer 650E 1962, Starter, Stator, Rectifier problem?

Update: the starter was fried. I have it in a shop being rebuilt right now.

I am still not sure what happened to the rectifier, I thought I was very careful when I hooked it up. It was a $5 so it could have been worse.

I am going to wait until I have the starter back in before I try to hook up the rectifier again.

Thanks for responding to my post guys.

I will keep you guys updated.