Generator upgrade?
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Author:  ansim [ Fri Aug 19, 2016 2:24 pm ]
Post subject:  Generator upgrade?

Hi Paso members,

After change to Megasquirt on my Paso, I noticed in the log files from the box that the supplied voltage was lower than 12V, mostly around 11.6-11.8V. When I hooked up a small voltage meter and had it on the dashboard during runs I noticed that when I switched of the head lamp the voltage increased to above 13V which is good. I have upgraded the rectifier to a Shindengen FH012AA.

The original generator is stated to give 300W. Is it possible to upgrade it to a more powerful one, like 350W or even more?
What is needed to get it working?

Some Monsters have a 350W generator and I saw in some specs that some engines have a 510W generator.


Author:  higgy [ Fri Aug 19, 2016 6:13 pm ]
Post subject:  Re: Generator upgrade?

Only option is to have the stator rewound as a single phase using different gauge wire and more turns. Every other option means a new stlyle crank with the stator end crankcase modified to accept the later style 3 phase stator

Author:  Frank.61 [ Sat Aug 20, 2016 6:28 am ]
Post subject:  Re: Generator upgrade?


I do not want to raise more questions but since I'm completely restoring my '89 Paso 750, I have 1 question on this topic. :?
What is the more sensible thing to do: e new (electrex) conventional rectifier/regulator or converting it to a mosfet rectifier/regulator?
I read the article but not sure about the advantages to switch to the mosfet solution (little more complicated/expensive). :dunno:
I have the engine, frame, suspension, wheels almost ready and after mounting the Weber, the next thing is the wiring etc.
I'm going to make the improvements Gerhard sugested (relais for ligth and starter engine and improved mass wiring), I just want a reliable bike not a modern one.
Also Ansim talks about 300 W, why is that not enough?
Lights will use approximately 100 W so that leaves roughly 200 W for recharging and ignition.
Just curious .... :thumbup:


Author:  higgy [ Sat Aug 20, 2016 10:34 pm ]
Post subject:  Re: Generator upgrade?

a Mosfet regulator will keep tighter control of your stator output and prolong its life. Can't say much about the electrosport brand. I prefer the Shindengen

Author:  Frank.61 [ Sun Aug 21, 2016 7:11 am ]
Post subject:  Re: Generator upgrade?


But is it just plug and play?
I have 3 yellow wires comming out of the stator.
The item about it was a bit confusing for me, with the 1 or 2 or phase construction.


Author:  higgy [ Sun Aug 21, 2016 8:33 am ]
Post subject:  Re: Generator upgrade?


explanations can be found here

Author:  ansim [ Sun Aug 21, 2016 8:06 pm ]
Post subject:  Re: Generator upgrade?

The Shindeng I have seems to work fine.
Regarding the fuel injection, the fuelpump takes about 1.7A and the injectors uses 2x0.8A and the MS box probably less then 1A. Perhaps the battery is about to give up.

When I changed to use H4 LED lights instead of normal H4 there was no problem with the voltage. It was above 13V during the test run.

Author:  ansim [ Mon Aug 22, 2016 3:54 pm ]
Post subject:  Re: Generator upgrade?

Reason for asking is that I found this link a while ago:

Author:  higgy [ Mon Aug 22, 2016 6:57 pm ]
Post subject:  Re: Generator upgrade?

the early ST stator (98 model)is actually slightly smaller than the 907 and used the same magnet
Better off having your stator rewound

Author:  ansim [ Tue Aug 23, 2016 9:54 am ]
Post subject:  Re: Generator upgrade?

I'll start with to check the charging system for any 'leaks'. Brad Black diagnosing procedure http://www.bikeboy.org/chargingsystemdiagnostic.html

Author:  higgy [ Tue Aug 23, 2016 10:22 am ]
Post subject:  Re: Generator upgrade?

excellent place to start, Brad knows what's up and is always very helpful

Author:  Derek [ Tue Aug 23, 2016 11:39 am ]
Post subject:  Re: Generator upgrade?

higgy wrote:
the early ST stator (98 model)is actually slightly smaller than the 907 and used the same magnet
Better off having your stator rewound

The first ST2, for 1997 had the same 350W single phase alternator as all the other Ducatis of the period (748/916, Monster, SS). The 907ie has the same 350W alternator.
For 1998 only, the ST2 had a single phase 450W alternator. This gave no end of problems from the stator burning out due to overheating and there was a subsequent recall to fit a special distance piece behind the rotor that would throw oil over the stator to help keep it cool. From 1999 on the ST used a 520W 3-phase alternator which can't be retro-fitted because it also uses a different crank, crankcases and alternator cover.

Author:  higgy [ Tue Aug 23, 2016 1:42 pm ]
Post subject:  Re: Generator upgrade?

the ST2 had a single phase 450W alternator.

while it will fit it is physically smaller than what came in the Paso's I have one here,it may use a larger wire don't know for sure,maybe I'll put up a pic of the two side by side so all can compare
I've been down this road and all the possible options. Read everything I could find on modified setups and posted it here
Yes it is possible to change over to a more modern 3 phase but it is a big expensive project and really unnecessary

have your stator rewound if it has an issue, you can even have it rewound with more turns of the wire size of your choice but there can be issues with changing wire size. I had mine rewound to stock spec and replaced the regulator with a Shendengen. Why the rewind ? 25 year old insulation and it was cheaper than a new "who knows how long its been on the shelf" replacement. Why Shendengrin ? They have proven to be the best bang for the buck and now have newer true regulators not shunt type found almost everywhere else. Shunt type regulators add heat to the stator when you are not using what the stator puts out. Mods like LED bulbs will add more heat to the stator due to their lower demands. With a shunt type regulator your battery condition determines what the stator puts out and the shunt dumps the excess to ground which produces the heat that kills regulators and stators and batteries. Mods like changing the total load with LED's means more goes to ground and more heat.

The advantage of a Mosfet is tighter control of the voltage and less overall heat

the newset Mosfet's also are true regulators and not shunt type. More expensive ? Yes but will give you the longest life for your system when having to sort it all out

I run dual silverlight bulbs with LED's everywhere else and have no charging issues anymore on the 906 or the 907. Have not had the time to do the 750 as yet

Author:  Mc tool [ Tue Aug 23, 2016 8:30 pm ]
Post subject:  Re: Generator upgrade?

One thing I have become aware of with the shindangding-a-ling regs is that they have a voltage sensor wire which tells the reg what voltage is in the main power feed , not what is coming out of the reg , and this wire is supposed to be connected to the switched side of the ignition switch, now on the ole Paso , renown for volt drop issues if your missing a couple of volts at the switched side ( more than likely ) the reg will keep upping the output V until it sees 14.5v at the test point ............ which means the battery is getting that 14.5v PLUS whatever the drop is , so ( I am using one of these regs on my quad ) I have fitted the sensor wire straight to the + batt terminal and its all very good . If you are having over voltage charging issues try moving the sensor wire and see if this helps ..... and then fix all the bad connections causing the fault :)

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