Radio Shack Rectifier for 850 Merc

[hereto]

Hi All,
Have a 1976 850 Merc, this has the ADI ignition. Need to replace the rectifier, would like to save some bucks by going with the Radio Shack version I have been reading about in the forums. I have contacted 2 near by stores and told them I was looking for a 25amp 200v Full-wave bridge rectifier, Both Radio Shack stores could not come up with a 200v model.
Both stores do have a 25amp 50v Full-wave bridge rectifier. I believe my stator puts out between 6 and 9 amps from what I have read. Can I use the 50 volt rectifier or if it must be 200 volt can someone help me out with a Radio Shack part number. Thanks in advance

hereto

 

[mercurymang]

Re: Radio Shack Rectifier for 850 Merc

I would think the 50v would be fine.

 

[tazrig]

Re: Radio Shack Rectifier for 850 Merc

I know and appreciate you're trying to save a few bucks but if it was designed for 200V you may be looking for trouble...

 

[hereto]

Re: Radio Shack Rectifier for 850 Merc

Don't know what the specs are for the factory rectifier, or what voltage it was designed for. Just trying to find out which Radio Shack rectifier will work with my motor. I have read a lot in these forums about the Radio shack rectifier even being superior to the OEM rectifier. I am not technical at all when it comes to electronics, just trying to find some help on whether the 50v rectifier will be satisfactory on my engine.

 

[Georgesalmon]

Re: Radio Shack Rectifier for 850 Merc

I would doubt that the stator puts out anywhere close to 50vac since its used to charge a 12vdc battery. Don't know for sure though. How much are you saving? Ebay usually has used merc rectifyers for around $10-20.

 

[Silvertip]

Re: Radio Shack Rectifier for 850 Merc

Unloaded, a stator type alternator can put out relatively high voltage. If the engine is NEVER run without a battery connected, then the battery will hold the voltage well below 20 volts so the 50 volt rectifier will work. If you ever run the engine without the battery connected you may pop the rectifier. Those rectifiers are dirt cheap so no big deal if it pops.

 

[hereto]

Re: Radio Shack Rectifier for 850 Merc

Have not had much luck with used rectifiers, really wanted to try the Radio Shack brand of rectifier as I have read on these forums that they actually hold up better. Any way I am hoping someone out there can help me out, as to which Radio Shack rectifier will work with my motor. Was hoping the 25a-50v Full-wave rectifier would be good to go as the Radio Shack nearest me has them on the shelf for $4.20

hereto

 

[mercurymang]

Re: Radio Shack Rectifier for 850 Merc

The full wave rectifier will have a higher rms than the half wave. Too that end I'm not 100% that you should replace a 1/2 wave with a full wave. I suspect it's ok. Do you know what came off of it. Also, be sure that whatever you put back on has a good heat sink.

 

[carholme]

Re: Radio Shack Rectifier for 850 Merc

If you need to be convinced there are many discussions on this matter and they work just fine.

http://forums.iboats.com/search.php?searchid=5257143

Gerry

 

[Chris1956]

Re: Radio Shack Rectifier for 850 Merc

Hereto, there is a lot of bad advice on this particular thread. Silvertip as usual, knows his stuff.

I ran RS rectifiers on my Merc IL4 and IL6 motors for 20 years. They work fine. The original rectifier was a full wave, with the -DC post connected to case ground. Replace it with the 25A RS full wave rectifier and it will work just fine. Remember to ground the - DC post to the cowling support. You will need to replace the merc ring terminals with spade female connectors.

 

[hereto]

Re: Radio Shack Rectifier for 850 Merc

Went out and picked up the Radio Shack 25a-50v rectifier this morning. Looks to be a pc. of cake to install. A very special thanks to
Silvertip,Carholme and Chris1956 for taking the time to reply on my post. You guys sure put my mind at ease as to weather or not to run with the Radio Shack rectifier.

Thanks again
hereto