Upgrading regulator rectifier

Had issues with the charging system on my 92 XV750, the regulator rectifier was shot. No problem I thought because I had a spare factory part. It wasn't any better. Did some research, ebay had lots of them and their prices were all over the place. $25 bucks or so on up so I picked out a few and started reading reviews and other research. Discovered that some of them had completely destroyed the wiring harness on some bikes, burnt out the computer controllers on some, ignition modules and pretty much everything else on some others. Best deal and advice was to get a Mosfet from Jack Fleming. Since the tsunami nuclear power plant disaster in Japan, he's the only one importing real genuine Mosfet regular rectifier. Everyone else claims that theirs is a Mosfet "type" regulator, not the real McCoy. Wiring connectors and terminals are first rate, instructions and support from Jack are excellent. Tested mine with a fluke 12 multimeter and it was spot on. No deviations at all. Appearance and build of the unit is also first rate. I don't have any dogs in this hunt, I bought mine like anyone else and paid the going rate but I firmly believe that no one has a better regulator and I will only have to buy one once. Mine was super easy to install. Since factory replacement regulators are for practical purposes extinct, if you're serious about your bike, this is the one to get if you're in the market.

 

VR for the XJs is still available from dealership. its a one size fits all (almost) kind of thing. and look like they last for 30 years or more with proper charging system maintance.

used ones are cheep too.

https://www.partzilla.com/product/y...?ref=59b1f39930ebc35a1f8d92ed426ed5e423488092

 

I looked at the web page for Roadstercycle (Jack Fleming) very nice stuff. The SH847 version R/R appears to be $217.00 +$11.50 s/h. I have an '82 750 Maxim and will use LED lighting.
Cheers, 50gary

 

The SH847 is for permanent magnet alternators, having no field winding control.

 

I paid $130 something for mine, the XV deals with excess voltage by grounding it to the frame. Since there are no brushes to deal with the trade off I suppose is having the alternator put out max (depending on rpm) all the time. Not sure what other bikes run the same system as the XV but the mosfet regulator would be a good replacement bet for them. I think it's a very reliable replacement for the factory part. I think if Yamaha had used it in factory bikes as OEM installed part we probably wouldn't have to worry about it failing. But the same could be said about better bearings, valve guides, seals, switches etc. But then nobody would be able to afford it. Hopefully someone will be able to make good use of this info. Thanks for looking...

 

Failure of stock components is actually quite rare.

 

My stock XV regulator lasted 60k miles. Not sure if that's really good or bad.

 

I went through this on my Triumph Spint ST1050. Most modern bikes have permanent magnet generators, I suspect because there are no brushes to maintain, and because the amount of power it robs is minimal, especially on a 100+ hp bike. Plus, it charges at over 13.5V at idle. Our XJ bikes won't charge the battery until 2k-2.5k rpm.

The key here is that a real MOSFET RR will cost $$. What you find on Ebay or Amazon for <$50 will not be MOSFET. They will say they are "OEM fitment" but not OE equipment, meaning the connectors fit and it is supposed to regulate to the right voltage. But how well it does that, how hot it gets, and how long it lasts are not related to it's "fitment."

Shindengen makes the OE MOSFET or Series R/R that you want, while there are some reputable aftermarket equipment as well. All will cost $150-300 generally. You can identify real Shindengen by the stamping and casting marks on the fins, as well as the heat sinks. You *will* need to know these things if you order them from ebay or amazon, so you're not paying >$100 for a $25 fake part.

 

Best bang for the buck is a used SH-775 from a Polaris.
Beware of the fakes, but there are plenty of real used ones on ebay from such sellers as powersportsnation.
On the GS Resources it's become the standard replacement for the last several years. I don't recall one failure of a used SH-775.
The SH-847 is the uprated modern replacement for that, being able to handle 50A, compared to the 15-30A (depending on cooling) of the 775 .

 

I did the used SH775 on my triumph, however I found it to have regulation issues. Just a warning on trying a used regulator, a voltmeter on the bike is a must. That could have been just cause it was used, or a sizing issue on the bike. I was trying a series regulator to make my new stator last longer.

the SH847 was a bit much so I found an FH020AA (mosfet) on eBay new for about $100

 

Ah, rings a bell - regulation falls short of optimal above 8000rpm?
I've heard that on the Triumph or Aprilia forums, but never had it on mine.
Of course, I don't really spend much time above 8000 anyway, and when it's above that it tends to be only long enough to get the next gear and in those circumstances I'm not looking at the voltmeter.

 

That’s what I was reading on the forums (the st redline is 10k, Daytona owners were particularly wary), but actually it was losing regulation around idle. Again, probably because it was used, but the voltmeter helped me catch it.