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Messages - Patches

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Main Message Board / Re: New Member seeking alternator input
« on: January 28, 2019, 07:10:32 AM »

Based on Ken's helpful reply, I chased down the Wilson remanufactured units through the NAPA and Wilson websites.  I learned the closest Napa unit to me was in Central Islip, NY, and I live in the Seattle area.  I also learned that it shipped without a fan or pulley.

I went back to Bobby at ASE in Portland and we identified the Arco # 60125 as a direct replacement for the Prestolite/LN 8MR2091KSS.  Like that alternator, it has a terminal for the external sense wire, but also comes new with the fan and pulley.  Same 2" foot, and small frame profile.  Bobby says the key difference are a 55amps, a 17mm shaft and 3" pulley.  ASE prices these at $166.95, and I had it by Saturday afternoon.  It looks to be very well made.

I'm waiting for a couple of parts to re-install my exhaust manifold before I bolt on the new alternator and wire it up.  At the time I will provide my final thoughts, including if a new belt is required because of the slightly larger pulley.

Many thanks to the those who helped to steer me the right way during this process, especially Ken, Mainesail and Stu. Your input saved me valuable time, and taught me a lot.


Main Message Board / Re: New Member seeking alternator input
« on: January 25, 2019, 06:55:22 AM »
Thanks Ken and Mainesail.

Let me say initially I appreciate your desire to steer me the right way the first time around, as well as the obvious depth of knowledge you bring to the discussion.  I also want to say that --at every future opportunity --I intend to support the good work of Mainsail when I upgrade my electrical and fully sort out my electrical needs.  I just don't know what that will look like exactly, and how solar or refrigeration or an inverter will fit in.  I just hope he is still in business when I pull the trigger--likely in a couple of years--because (1) I believe in rewarding good work and (from what my inexperienced electrical mind can tell) (2) he pretty much makes the best stuff for the job.

By your previous responses, it occurs to me that I haven't explained my use/intended use well.   Right now my boat is hooked up to shore power every day, and is used sparingly November-March and will be used often (up to 4-5 days a week) for daysails from April to October.  I work as a charter captain, and starting this year I will be using my boat as part of the business.  I will also have the yearly 2 week cruise in September with my wife.

I am currently making all of the wiring upgrades that Ken has mentioned that he made on a friend's Catalina 30.  I'll have all new engine and panel wiring, and a new instrument panel and gauges.  Which leaves the choice of alternator.  For the sake of simplicity, and until I can return to Compass Marine with a clearer long-term design in mind for my electrical system, I'm looking to (1) get the engine to start (2) to get me out sailing for a few hours at a time, and (3) without using much in the way of electricity while I'm out sailing.  The vast majority of the time I won't even be using running lights or a depth sounder.

Hence my decision to stay simple for now when replacing the alternator.

Ken:  I've not been able to find the 8MR2091KSS anywhere.  It was listed as the direct replacement, so naturally I thought of that first.  ASE doesn't have them, my local alternator shop doesn't have them, and after I ordered one online from a place that said they were "in stock", I was told they don't have them either and couldn't source them from a competitor.  So if you know where to get one, please let me know!

As for the re-manned Motorola 2049K's with the external sense wires, if these are preferred to the other 2 options I arrived at please let me know where to go for those.

Otherwise, I will work with ASE to get the "next best" option given what I've learned here.

Thanks again for your input!


Main Message Board / Re: New Member seeking alternator input
« on: January 24, 2019, 04:19:49 PM »
Thanks Stu and others.  I contacted ASE and received helpful input from Bob.  I measured my OEM shaft at 5/8" and the pulley at a 2 5/8" diameter.  After researching a few options, the choices appeared to boil down to the following internally regulated options:

1. A remanufactured Motorola 2049K in 55 amp or 72 amps.  This was mentioned by Ken and I was unable to learn much more about whether these are a direct replacement for my M25XP which has the alternator bracket upgrade.  However, they have the ability to run a voltage sense wire to the starter post to aid the internal regulation.

2. A new Arco 60050 55amp alternator.  This was recommended by ASE, and Bob mentioned that this is actually a "Mando."  He said it should be a close replacement, with the exception of the pulley which is 2 3/4" vs. the 2 5/8" pulley on my OEM alternator. 

3.  A new Prestolite 110-656 51 amp alternator with external sense wire.  It is slightly deeper in profile than my OEM, and comes without a pulley.  However, a Motorola "162" 2 5/8" pulley is available for the 5/8' shaft, and ASE with install it for me.  The mounting ear size is only 1", and the mounting bolt size is 1/2" vs 3/8" OEM.  But it looks like the the spacer kit resolves these small differences when mounted.

Any preferences/experience with any of these alternators?  Anything I haven't really considered?

Thanks in advance for your feedback.   

Main Message Board / Re: New Member seeking alternator input
« on: January 24, 2019, 04:02:16 AM »

You have properly grasped my situation!  As mentioned, my upgrading budget is much smaller now that I have begun some of the critical fixes.  The major electrical upgrades are a few years off.  The good news is I've been able to knock off a bunch of the other upgrades to the motor in this first year.  My thinking is also informed (in part) by the fact that the boat operated in its original "relatively low electrical demand" condition for 28 years for two prior owners.

One of the things you mentioned was an "external sense wire", and this seems to be important for the replacement alternator.  Conceptually, and after doing a little research, I think this means the alternator--being dumb--needs a wire to the battery "+" to figure out the state of charge (SOC) in order to know how much power to direct back to the battery.  Is this right?

As I looked back at my replacement choices set forth my original post,  the 72amp (8MR2058PA) does NOT have a remote sense wire.  Nor do the 51 amp or the 65 amp models that the local alternator shop was able to sell me off the shelf.  The 51 amp direct replacement version (8MR2091KSS)-- which I can't find anywhere--does.  So it sounds like your idea of a remanufactured Motorola is a good one.

And as originally designed, it sounds like the sense wire assessed the battery SOC through the starter "+" post where the 4 awg positive wires came in from the selector/switch, and prior to that the batteries?  So it assesses SOC there--a long (and winding) way from the batteries.  I think I get why a comprehensive upgrade, including wiring the AO directly to the batteries is in my future.

The other wiring things I'm tackling near the engine include:

(1) moving the 4 awg negative off the bell housing to the starter "-" where the other 4 awg negative is attached.  From there I'm planning to run a negative 6 awg to a negative bus bar mounted on the port side to pick up the other grounds.

(2) increasing the AO positive to the starter "+" (8 awg), as well as a 8 awg "-" to the new negative bus bar.

(3)  Yeah, I bought the Catalina harness because I bought a new instrument panel as well.  The old one was pretty bad.  So I intend to inline fuse the "+" panel feed (red #10 wire) within 7" of the starter "+" as recommended here, and run the new #10 yellow/red start wire (unfused) to the solenoid.

(4)  I tossed the euro strip which came with the new CD instrument panel.  My boat does not have the glovebox-type pocket in the access panel for the euro strip to sit in, so i used heat-shrink butt connectors to connect the new harness wires to the new panel wires, and will be securing the harness run every 18" to the engine compartment. 

(5) On the engine side of the new harness, I'm thinking of running the wires to a terminal strip on the port side of the engine compartment, aft, up high, to be accessible for future work.

Any thoughts on these ideas?

I SO appreciate the input, because there is so much to learn. 

Main Message Board / New Member seeking alternator input
« on: January 23, 2019, 03:18:53 PM »
Hello to all, and my apologies for the lengthy preamble to this request for input.

I recently became the owner of a 1990 Mark 1.25.  When purchased, it was in largely "stock," unmolested, condition including:
--two group 24 flooded lead-acid batteries
--original (and dangerous) engine harness with trailer connectors.
--original instrument panel in the cockpit
--Prestolite 51 amp alternator
--autohelm st4000 autopilot
--no refrigeration
--battery charging from the alternator via the 1-2-both switch on the panel.

My intent is to slowly upgrade the boat as the budget allows.  I live in the Pacific Northwest, and cruised this past summer for two weeks straight without any issues.  Longest time away from shore power was 4 nights.

Because of my lack of experience with inboards, electrical demands, and bigger boats, one of the first things I did (8 months ago) was purchase two new Group 24 batteries with 85 amp hours each.  (I know, I know, dumb)  This was a (more or less) direct replacement of what was there when I bought the boat, and it seemed to work fine for the sailing and cruising I did this past summer.

I also started to address some of the other priorities set forth by the surveyor.  I have purchased a new exhaust riser, exhaust flange, heat exchanger, engine soundproofing, engine panel and wiring harness, hoses, raw water strainer, and raw water pump.  To get the exhaust riser out, I had to cut it off near the flange on the exhaust manifold, take the manifold off, and then work for days to separate the flange from the manifold.  Eventually I succeeded.  Many thanks to the contributors on this forum to help me understand how to attack these things!

Which gets me to the present issue before I start putting everything back together:

I had to take the original alternator off to get to the rest of it.  When I did, it leaked oil.  I took it into an alternator shop which deals with Leece-Neville alternators, and the tech opined that it was not cost effective to rebuild.  It is also 28 years old.  Which raises the issue of the type of replacement.

After all the expenses recently made, the budget is not equipped to handle a serious upgrade to the battery bank, high output alternator, new pulleys and belts, external regulation, refrigeration, etc.. I would like to get a few more years out of the present configuration, which assumes the new alternator charging the "smallish" battery bank by installing a larger output wire (e.g. 8 awg-or larger) to the positive post of the starter as recommended by others.  And I would like to buy a replacement alternator to accomplish this goal until I'm ready to spend more money on a more comprehensive electrical upgrade.

My attempts at researching this suggest the following which, admittedly, may be ill-informed:

1. Sizing the new alternator depends on (1) the size of the existing battery bank and (2) the footprint of the old alternator.

2.  For lead-acid batteries, a rule of thumb is to size the alternator output at 25% of the battery capacity.  For me, this is only 170 amp hours.

3.  Prestolite/Leece Neville manufactured several internally regulated alternators which allegedly fit in the "footprint" of the original alternator.  These are a 51 amp model, a 72 amp model, and 90 amp model.  The 51 amp model I can't find anywhere.  The 72 amp (8MR2058PA) and 90 amp (8MR2069TA) models are still available.  These can be had for <$200 each.

My questions for those experienced in these things, and given my desire to tackle a more comprehensive battery/electrical upgrade later:

1.  Do I risk any harm to my electrical system or batteries by replacing my existing 51 amp alternator with another internally regulated 72 amp (or 90 amp) replacement from Prestolite?

2.  If so, what is the expected harm?

3.  Would a switch to either of these higher output alternators require upsizing wires?  I have the 4awg positive and ground wires from the panel to the starter motor and engine block, respectively.  How about the AO wire to the starter?

4.  Leece-Neville also makes other 51 amp and 65 amp (8MR) small frame alternators, although they have different dimensions (deeper and three mounting holes along the top).  Anyone have experience trying to fit these into the M25XP alternator bracket?

5.  Given your experience, what would you do in my situation?

Thanks in advance for your replies.  I really appreciate the depth of knowledge and willingness to share found here! 

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