Would anyone be able to tell me if there’s a weight difference between the various K engine alternators?
I have a 50 amp but wouldn’t mind switching it out for a 32 if those are lighter...

According to the MAXBMW parts fiche, the 50A weighs 12.24lb and the 32A weighs 7.05lb.

That would be a weight saving of about 2 kgs, the same as 2.5 litres of fuel. Best to put less in your tank or get rid of that huge tractor battery that most Ks use.

That’s awesome! Thanks for the info
I’m slowly “pre” assembling the bike and was surprised by how heavy the thing is. Truly an automotive piece...

Yes, it may not be worthwhile for most but I’ve reached a point in weight savings where I‘m having to take a look at any essential components..

Dunno if you've considered a lithium iron battery, but the first time I picked one up I just laughed - it was so light.

Definitely! I’ll be using an Antigravity lithium ion that weighs 2lbs 4oz according to specs and it’ll have a highly simplified electrical system once completed.

I've been using a 12 amp Li-ion in Big Block since new - five years - and it has never lost any juice, weighs 3 lbs - stock was nearly 14 lbs. I use a lithium-specified charger (no pulse, which works well on AGM or FLA, but shortens the lithium cells' lives) on it about three times a year.

Good to know, thanks for the info!
Also, many thanks for your Big Block K thread, it’s very informative and has been really helpful while swapping mine.

In case anyone would like to know:
50A - 4,150 grams
32A - 3,205 grams

Bedlam.Bambi wrote:In case anyone would like to know:
50A - 4,150 grams
32A - 3,205 grams

I tried to weigh my alternator by riding my moto onto a junkyard's scale, then subtracting the weight of all its parts as indicated in the BMW parts fiche from the scale's total, then I realized that the alternator's weight was also published in the the parts fiche. It isn't quite the same as what you have posted, but I wish you'd have posted this data sooner, anyway.

The upside is I found at the yard what I believe to be the driver's side door handle assembly of a 1989 Dodge Omni. Those are really rare.    Now, I'm looking for an Omni that doesn't have one so I can negotiate a sale with its owner.

Oooh, too bad it wasn’t a third brake light from the GLH-T variant. Someone dressing up their ‘84 GLH might pay big bucks for one of those.