120 merc Alternator Conversion?

[madmans]

I have a 1984 120 mercruiser outdrive. It has a stator? and magnets in pulley to generate electricity. I wish to replace it with a alternator (marine one) Is there a commercially available conversuion kit or has anyone done this modification before? I heard (word on the street ) that the stator units are quite troublesome? Thankyou New Boat Owner ,OH I got it running well and already had to winterize due to freezing weather never got to try it out. Now winter time new aluminumn floor project. Mike

 

[Bondo]

Re: 120 merc Alternator Conversion?

I have a 1984 120 mercruiser outdrive. It has a stator? and magnets in pulley to generate electricity. I wish to replace it with a alternator (marine one) Is there a commercially available conversuion kit or has anyone done this modification before? I heard (word on the street ) that the stator units are quite troublesome? Thankyou New Boat Owner ,OH I got it running well and already had to winterize due to freezing weather never got to try it out. Now winter time new aluminumn floor project. Mike

Nope,... If it's got a stator, it's a Merc 470, Not a GM based 120hp, 153 cid motor...

Post the serial number off it...

 

[achris]

Re: 120 merc Alternator Conversion?

Sounds like you got yourself a 'bitsa'.... Bitsa this and bitsa that... The drive might say '120' on it, but it's like to be an MC1 drive. The engine, as Bondo has said, it the notorious '470'. A Mercury 'one-off' design and build. Post up the serial number and/or photographs (preferably both) of the drive and engine. If the drive is from a 120, then the gear set is likely to be the wrong ratio too. 120 ran a 1.98:1 reduction and the 470 ran a 1.84:1 reduction... Looks like your learning curve just got a whole lot steeper...

Chris........

 

[nola mike]

Re: 120 merc Alternator Conversion?

But that's the easiest 50 hp upgrade you're ever going to get!

 

[thumpar]

Re: 120 merc Alternator Conversion?

They do make kits to convert the 470 to alternator. Spend some time reading up on the 470. It is a unique animal.

 

[achris]

Re: 120 merc Alternator Conversion?

Yes. Eric 3.7LX is the full bottle on them. I've PMed him and I hope he'll be along to help out...

Unique is one word for them... Maybe not my first choice...

Chris......

 

[Eric 3.7LX Alpha 1]

Re: 120 merc Alternator Conversion?

Thanks mate^^

breezeworks.net has lower and upper kits, depending on if you have power steering or not.

They offer a nice kit and many on here have purchased from them and have had good results. Comes with everything needed including instructions.

After my 2nd voltage regulator died I decided to do the switch and actually made my own brackets by copying this kit:
http://www.ebay.com/itm/MERCRUISER-..._Accessories_Gear&hash=item3a7aa699e8&vxp=mtr

and picked up a belt by using a piece of wire around the pulleys to get close, and a marine alternator to finish it off.

Actually the stators are not the problem they seem pretty durable... it's the voltage regulator that kills the system. I liked the idea of not having a belt to worry about when I first got the boat. Now I like the idea of having a Delco alternator that can be rebuilt for cheap $$ and I keep a spare belt in the boat tool box.

 

[madmans]

Re: 120 merc Alternator Conversion?

Hi Guys I dont think mines a 470 it has a cast iron block, The 470 blocks aluminumn? I think I have the 2.5 litre with 120 horse and weirs charging system under the pulley thing. Help??

 

[thumpar]

Re: 120 merc Alternator Conversion?

Hi Guys I dont think mines a 470 it has a cast iron block, The 470 blocks aluminumn? I think I have the 2.5 litre with 120 horse and weirs charging system under the pulley thing. Help??

The 120 and 140 both run a standard alternator. The 470 and variations of it are the only ones that run stator charging system.

A picture or serial number would help.