150 optimax........alternator bolt snapping

[Ynot]

ok guys ........how many of you have heard of this problem.I found the alternator bolt snapped off doing the winter storing thing last fall. Replaced it then ......and now with 10 hrs on it another broken bolt ! Please need help....a friend had the same problem .......and they had to replace the powerhead due to the casting on the block that broke instead of the bolt.....