I have a friend that has a 98 748 and it runs fine then just dies after awhile. I replaced the battery fired right up took off ran for about an hour then died again? I'm thinking a short somewhere or possibly the rectifier bad? Any thoughts or ideas?
I ran into the same symptoms with my 748S...the battery wasn't charging which can be from a number of things. I went through the list of possibilities...first assuming that it was the rectifier, but there was proper voltage coming out of the rectifier (and going into the rectifier). In my case it ended up being the large fuse to the right of the battery that is inline between the rectifier and the battery. Replaced it and problem solved. So I'd check that fuse first as it is a very quick check. Then I'd measure the voltage going into the rectifier and coming out of the rectifier. If all three of those are ok there are some threads that get deeper into the topic and include additional checks.