'85 Merc 170 Alternator Conversion Question

[Vampyreguy]

I bought this kit and would like to know what type of alt. to buy. I really don't think i need a full 70amps. The boat only has running lights so far and maybe a VHF/AMFM/depth sounder in the future. I'd like one smaller in size too due to ltd. space under the engine cover. The boat is a '85 Fourwinns 190 Horizon. Link to the side mount kit, which uses the stock pully on the balancer, below. Any advise would be helpful. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2483089540&category=31284&sspagename=rvi:1:1

 

[Bondo]

Re: '85 Merc 170 Alternator Conversion Question

Ampereage Output has Little or Nothing to do with the physical Size of the Alt........<br />I Wouldn't buy Less than 70amps........

 

[MrBill]

Re: '85 Merc 170 Alternator Conversion Question

Vampyreguy...Most of the (470/3.7L) conversion kits come with a 68 amp alternator. You may have purchased an incomplete kit if you have power steering. If your boat has PS, you'll need to mount the alternator on the lower left which may require a separate pulley to be mounted on the balancer. Breezeworks sells two conversion kits without alternators (one like yours $89, another with the pulley w/additional parts $150). This Spring I purchased a complete Wagner kit and it works perfectly ($370)...shop around, there's no need to pay over $375 for everything, although some charge as much as $529 for the SPEDC-60. Install was easy...under one hour, leave the old stuff in place.<br /><br />Check these links or type 'alternator conversion, 3.7, 470' into a search engine like Google. <br /><br /> http://www.jimthompson.net/boating/Electronics/Alternator_conversion.htm <br /><br /> http://marineengineparts.com/shopsite_sc/store/html/page99.html <br /><br /> http://i-netmarine.com/AltKit/altkit.htm <br /><br /> http://www.breezeworks.net/index.html?target=p_12.html&lang=en-us

 

[Vampyreguy]

Re: '85 Merc 170 Alternator Conversion Question

I bought this kit w/o alt for specific reasons. I don't have the clearance for the addon pully <3". The gas tank is directly in front of the engine. Also 70amps seemed like overkill for the applcation. I'd like to shop around for something that fits under the engine cover without any mod's to the floor.

 

[kcole683]

Re: '85 Merc 170 Alternator Conversion Question

I would say 70 amps is plenty for your boat (more than enough). The original system was only 39 amps to start with. Of course the original system usually runs at higher voltage and it will definitely keep a good charge.

 

[MrBill]

Re: '85 Merc 170 Alternator Conversion Question

Maybe you'd be better off with one of the new and improved voltage regulators for the old system. I am told they're much better than the old ones, solid state, won't blow up like the original equiment (Rapair Voltage Regulator #R99502A4). <br /><br />From Breezeworks (Under voltage regulators) <br /> http://www.breezeworks.net/index.html?target=p_12.html&lang=en-us