Ken: I've not been able to find the 8MR2091KSS anywhere.
The 8MR2049XX or 8MR2091KSS or 8MR2091XXX, & other similar suffix units, are just one of the many 8MR units that Leece-Neville has discontinued. You also need to be careful with some of the 51A units as the internal regulators on some, such as the 8RG2010, were factory set at 15.0V. Components are avaialble to build them, but in the end they cost about the same as a higher amperage model. I just ran the numbers on a 2" foot 72A, with the LN 8RG2043 adjutable regulator, pulley, 10mm to 3/8" sleeve, etc. and it comes in at about $296.00 but components such as stator, rotor, negative rectifier and front & rear frame are not currently in our in-stock..
Start at NAPA -- it lists all the Wilson remans for the LN alts, including the -KSS.
Go to www.napaonline.com and plug in the LN model #. If it doesn't come back, go to the Wilson site, www.wilsonautoelectric.com/SearchPart plug in the LN model and get the Wilson # to plug into NAPA. That's a guide - NAPA is higher $$'d. Rather than chase tails in circles with models -- once you boil down to which (if any) p/n you want - let me know, I'll pass you the best Wilson source I have for that (will sell it less noticeably less $$ than NAPA.) Wilson doesn't sell direct, but again the nice thing is that you should be able to get the unit shipped that tested out closest to the setpoint you want. for example, I got one off the Wilson warehouse shelf that was 14.1, instead of 13.8.
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.
I was just posting that one supplier in AZ sells the Leece kss Wilson reman for 114 (+ 40 refunded core charge.). Drop ship $ from Wilson is reasonable.
I know Wilson says it ships w/o a pulley, but have always received the OEM pulley with the Leece remans.
What setpoint did the new one test out at?
The pulley will need a tach recal.
I’d use a Dayco Top Cog belt when you reinstall!
The Arco/Mando 60125 alternator is NOT a direct drop in for the Prestolite 51 amp which was original to my boat. While everything else was a fit, the ear/tab size was about 3/16 wider than on the original alternator. This created alignment problems with the belt. Also, the pulley diameter was 2 7/8" vs. 2 5/8" which Ken pointed out would have required a tach recalibration. Although Leece makes a 2 5/8" pulley you can put on, it would not fit on the 17MM shaft of the Arco. ASE was very cool about it, and because I had not tried to mount it they allowed me to return it for a full refund. Good people.
I tried initially to find out if my original alternator could be rebuilt. As I mentioned, my "local" shop--which is still a 40 minute drive--said it wouldn't be cost effective and recommended a new one. Instead he tried to sell me one I knew wouldn't work because it had no external sense wire.
1. IMMEDIATELY get rid of the trailer connectors - FIRE Hazard!! You can easily just hard wire everything and do not need a new harness kit - especially if you already have a Volt meter!!
2. With NO Refrigeration you should have NO problem with the 51 Amp OEM alternator for recharging your small 2/group 24 house bank doing a couple of day overnight between shore power recharging.
3. Read all of the posts on redoing your electrical system. There is a TON of information on this site and the Mainsheet Tech notes on what to do and how to do it!!
I re-did my electrical from the Instrument Panel to the engine, using the many helpful suggestions of the members on this forum. New instrument panel, new wiring harness, fuse on the panel feed wire (red 10 awg), new negative buss bar coming off the starter to pick up other negative wires in the engine compartment, new alt output wire (8 awg) and alt neg (8 awg).
Everything does what it should when I turn the key to "on". Just waiting for the alternator to come back!