Why only rectifier on 78 Jota

T

Tetley Laverda

Senior member
Hello
Can anyone explain why Laverda only fitted a recitfier and not a reg/rec on my 78 Jota I have upgraded the charging coil giving 150W output would it be recommended to fit a reg/rect or is the standard rectifier safe enough . I measured charging system going up to 17.5 V when blipping the throttle with battery fully charged.
Many Thanks
Tetley
 
'Cos they reckoned with the stock 30Ah battery you wouldn't need a regulator... these motherfuckers aren't very fickle when it comes to charging current, they act as a buffer.  No regulator = one less thing that can go wrong. :D

Been running my 3C with DMC alternator upgrade for decades on a rectifier only, works OK even with a 14Ah battery.

piet
 
I can only second what Piet said. I've been running the DMC upgrade as well for ages on a rectifier and for the last 5 years with a 18Ah AGM battery. The Shindengen 530 R/R that I have stashed away still waits to be installed......

Regards,
Gerald
 
It also turns the indicators into strobe lights the faster you go. well it does on mine :D

                                                                          Dave
 
Dellortoman said:
The alternator output was pretty piss-weak anyway. Just enough to charge the battery and not over-cook it.
Click to expand...

you missed the word 'occasionally' out before the word charge.
 
Back in 05 I installed a DMC with the additional charging coil on my 3c.

Went for a long ride and fried the OEM Bosch rectifier (tiny thing too)..overvoltage (like yours) killed the Bosch unit and had an adventure coming home. Been a while since I rode with a total-loss charging system.

Fitted a true voltage regulator/rectifier for that other Italian motorcycle..Electrex RR51 and used the charging wire for the warning lamp too..works well.
 
I use a regulator/rectifier to stabilize the output voltage at 14.4 volts, I would have thought 17.5 volts through the bikes wiring would be exploding bulbs, and I would not think it would be good for the battery? Having been stranded far far from home on my RGS when the regulator/rectifier failed and allowed unregulated voltage to cook the battery, I am a big fan of higher end regulator/rectifiers that  actually regulate DC output voltage. Also, typically part of my small spares and tool kit for longer trips includes a spare r/r, which since I started carrying it, I haven't needed. ;)

here is an interesting article on motorcycle charging systems

http://www.electrosport.com/technical-resources/technical-articles/how-motorcycle-charging-system-works

you can use pretty much any r/r that would fit an old Suzuki of the same era. The Electrex products seem to be top quality, the RR51 allows 2 connections from the alternating current charging source, I green wire to connect to a charge warning light, and red and black for power and ground. The Electrex RR 10 allows connection of three wires from a three phase alternating current charging source, then just red and black for power and ground, no charge warning light. The Shindgen regulator rectifiers from various mass production motorcycles are also a great and inexpensive alternative, that is what I carry on the bikes as a spare.

Paul LeClair
 
Dellortoman said:
The alternator output was pretty piss-weak anyway. Just enough to charge the battery and not over-cook it.
Click to expand...

Quite wrong, Cam.

In the days of wet acid batteries, the bike would boil the 14Ah battery quickly if I forgot to switch on the lights.  Doesn't happen any more in these days of mandatory daytime lighting.  The AGM battery withstands a lot more punishment, the present one has survived for more than 6 years, with 4 or 5 Bikers Classics events at Spa Franchorchamps thrown in, don't run with lights there, and WOT most of the time.

There are ways of optimising the weak OE set-up, I have put up with it for more than 30 years and it has never let me down.  Just need to be aware of the limitations...

piet

 
Paul LeClair said:
The Electrex products seem to be top quality, the RR51 allows 2 connections from the alternating current charging source, I green wire to connect to a charge warning light, and red and black for power and ground.
Paul LeClair
Click to expand...

Just to clarify, if I was to fit one of these, would I have my charge light back again??
 
Rusty Spokes said:
Yes..with the RR51...works just fine for my 3c with the GEN lamp that was never wired or used.
Click to expand...

And it works with Kawa 250RR 3 phase alternator that my bike has been upgraded with? If so then I need one!! I like the idea of having a gen light and even installed one in my new dash panel just in case that option was available.
 
Dellortoman said:
Rob, you need a Shindengen SH541, which is a 3-phase RR with an output for a generator light.
Look for a Honda VTR 1000, SP1 or SP2 regulator from around 2001/2002

http://www.ebay.com.au/itm/Honda-VTR-1000-SP-1-SP1-2001-Regulator-Rectifier-/150764181878?pt=UK_Motorcycle_Parts_13&hash=item231a3ed976

Gen light output is the black wire.
Click to expand...

Thanks for that Cam, About to spend far too much on a replacement head out of UK so the Gen light will have to wait for a while yet, unless I can find a cheap 2nd hand one :)
I'm suppose to be building a house so more money for the Motodd unless it's spare change :D Not telling the misses about the new head 8)
 
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