ELM Products Compatible with Yanmar Diesel Alternator 12V 80 Amp 129772-77200 129470-77200 18-6278

Can not give any review as to longevity of this product since I just finished installing it. However, it is currently functioning properly. What I can review is the three days it took to get it in. As to it being a direct replacement for Yanmar marine engines, that is a bit of a stretch. On my 3JH3E there were a number of modifications needed. As to a sellers comment in the questions section, there were no pictures or instructions in the box and the rear of the alternator is not clearly marked, except for the bat and earth leads. The pulley that comes on the alternator is not correct for the 3H3E engine (and probably not for any other Yanmar engines in that class). You'll have to swap out with your old one or go to an alternator shop and get one that fits the belt. I bought a slightly longer belt to make installing and tightening the belt easier. The T plug on the alternator is extremely tight, so look forward to having trouble getting the "T" plug in (BTW the leg of the "T" is the lamp circuit(blue wire), and the crossing of the "T" is the charge(red wire). Since the alternator is slightly bigger than the OEM one, you need to grind down the "bat" terminal or it will touch the heat exchanger(which is really a "bad thing"). I also needed to put a new pig tail on the "T" connector to reach the "T" plug(probably because of the longer belt). Be sure and connect the negative(black wire) lead to the insulated negative terminal and NOT to the "E" (earth) terminal. Have Fun(I didn't)

The alternator was out of balance and in time would have caused excess wear on the pivot bolt.