Fit brushless alternator to big block?

I’ve an '81 Spada 1000 - can I fit a later brushless alternator?

[you can buy brushless type as aftermarket but the later guzzi brushless are parelell shaft and yours is tapered i think i have seen a adaptor somewhere

will post details when i find them


quote=Mr Noisy]I’ve an '81 Spada 1000 - can I fit a later brushless alternator?
Thanks[/quote] Ex smokingbiker2013-05-02 21:42:05

The Saprisa is a direct replacement as far as fitting is concerned. But there is little benefit in terms of power output. You can fit the later more powerful Ducati alternator, but you need an adapter to change the taper to parallel on the crankshaft as Ray says above.

Silly question time ~ why?

As in my case the standard is 20 amp flat out the one i fitted is anything up to 32 amp flat out or more importantly as i am a bike plodder and not a kneee down racer i tend to spend a lot of time in 5th gear and was finding that as i was not reving it i was suffering from the battery not being fully charged to the point you could hear it straining on start up (put it on charge for a couple of hours and it was fine then)
the one i fitted with the electronic regulator will at 2000 revs be capable of producing 20 amps since its been on the bike i have not suffered from a semi flat battery hence why i did it as it suits my ridding style

Never had any problems with the Bosch system and I have all sorts of extra elektrikiery bits added there IS a direct Bosch replacement from the Convert ot Police G5’s that is higher rated and kicks in from 1200 revs You can often find them at Breakers.

280W as opposed to some fitted to later Calis that were 120 watt, add spotlights and when you put them on the engine dies …

As GB never had this problem even pootling about everywhere at 3,000 rpm. Mind you I don’t usually have all the lights on in daytime. If that’s what’s doing it. (?)

PS: an amendment to the above ~ I have tended not to do lots of short journeys either.


I have the side lights on as well as a front riding light and two rear marker lights and on the Winter Commute the head lights 2 tail lights PLUS additional tail stop light AND often the angel eyes as well as the 2 35w spots. add to that the radio and still never had any problems with charging whatsoever. Not yet fitted the tree to go along with the lights tho’

The altenator on older bikes often does not have the later plastic spacer to keep it cool and THAT will lead to the wires literally melting with subsequent loss of power.

Make very sure you retro fit hte plastic spacer so more air gets to the altenator, mind even actually cracked the org alt cover due to the heat generated so i fitted a finned aftermarket cover as well as the spacer with the higher O/p altenator.

As the old style reg/rectifier is old school not solid state I had the diodes checked and replaced but that was 20 yrs ago.

The old board behing the r/h side panel CAN be checked and repaired by an old style tv/radio repair shop