900ss Reg/ret

There is no best unless you buy a mosfet one which is slightly different technology. It does not matter if you fit a 3 wire one on a two wire bike even.
I bought what was claimed to be a mosfet one from ebay China for £29 and fitted it to my two wire 1967 250 which has a 40 watt alternator and it works fine.

 

98 should be 3 wire.
S/h shindengen.

 

I've just fitted a mosfet (FH012AB) from a triumph 675 with a triumph adaptor (T2500676) as plug and play and it works on my monster S4 which I believe is three phase.

Adaptor was about £10 from triumph and reg was £30 second. Hand from a breakers.

 

The great (ongoing) aftermarket Regulator/Rectifier debate! ANSWERED??? - Ducati.ms - The Ultimate Ducati Forum

 

Just to complicate things.
These mosfet regulators work great but there are two types.
Shunt regulators : Shindengen FH series, FH012A, FH020A, etc.
and
Series regulators: Shindengen SH series, SH775, SH847, etc.

The shunt regulators are commonest sort and work by converting unused energy into heat. So the alternator is working flat out all the time and the regulator gets very hot.
Series regulators work by limiting the current output of the alternator to meet the demands of the bike. So if the battery down after a cold start and the headlights are on the regulator might be supplying the maximum power that the alternator can achieve, however when the battery is well up it will reduce the output from the alternator by restricting the current from it.
All alternators suffer from Hysteresis losses. Simply put this means that the more current you take out of them the hotter they get. Single phase (2 wire) alternators carry much higher currents than 3-phase alternators where the power is split across 3 sets of windings so are much more susceptible to heat damage. Ducati probably reached the limit of the single phase alternators with the 1998 ST2 which had a 450W alternator that frequently burnt out, such that there was a recall on them to fit an oil thrower behind the rotor to cool the stator down.
So if you want to give your single phase alternator an easier life and maybe last a bit longer fit a series regulator if possible.

 

There were some cheapies on amazon that that both @chrisw and I had a dabble with. They were awful!
Sorry,don't recall the part number.

 

I thought the MOSFET FH012/FH020 type were the least common and ran cooler than majority fitted up to approx 3 years ago?

 

Yep, second hand ones from a ZX10R, Triumph D675 , Yam R6 are the way to go.

 

The FH012/FH020 are less common among shunt regulators which nearly all regulators are. I don't know if they run cooler or whether they can dissipate it better but if it has to burn off 300W the heat has go somewhere.

 

My 1198 has a series one fitted from electrex. Needed some mods to the connectors to fit. DUCATI John sorted it for me.

 

Look at this on eBay SHINDENGEN MOSFET FH020AA REGULATOR/RECTIFIER KIT REPLACES FH012AA | eBay

This is the one I have fitted trouble free for the last five years. Read it's description regarding heat, runs cooler and cuts out if it overheats.
Steve

 

All the Shindengen regulators + kits + cables + fittings are available from Roadster Cycle in the US.

 

Well my £40 triumph FH012 seems to be working fine and a fraction of the cost. To help matters I've relocated the reg into a better path of airflow too. Should keep the wolf from the door.

 

Get one harvested off a newer bike, ZX10/Pani/R1 ect. Adapter leads form triumph. Doable for ~£50.

 

Better air flow on my 748.

 

I would say that is the same as my £29 one from China.

 

Note that this is a two wire alternator but the regulator is a three wire one, it makes no difference.
I will fit one of these to the wifes ST2 this summer.

 

Same arrangement on my 907ie. I had to cut some of the fins to clear the mirror mounting so that the fairing panel would sit fully home.