Got safety recall today in mail charging rectifier


Charging rectifier recall for my busa. Says do not ignore, so must be highly dangerous. those things can cause a fire if they burn right? I'm sure others will get one too! Suzuki headquarters about 2 hours from me, so guess I got one quick.

mike miller

I got one too. What are the odds suzuki would send the part to the shop I work at being as I'm certified auto and mc tech.. Might be worth a try


oRg Gal
Staff member
That's sounds serious VaBusa !! Australia got the notice last year , mid year , and I got mine done . :thumbsup:
Sorry I'm so late responding; life has been beyond busy :( Thankfully, @Twobrothersbusa was behind me, saw the smoke and flagged me down before it caused major damage. My Busa was loaded up and hauled back, and we were on the last day of vacay, so win win I guess...couldn't have happened at a better time or under better circumstances :crazy::laugh:


Donating Member
Stock, thyristor regulators generate heat, that is what they do, that is why dissipating fins are necessary. Prolonged charging situations, or batteries with higher resistance (as when they get old) can cause your bike's charging system to do extra work. So more heat in the entire system is generated. That is why you see melted connecting plugs and wires. So yes, you can let Dumbzuki replace your stock defective regulator with another of the same type. Or, you can fix the damn thing by changing over to a mosfet regulator, which does not generate heat :

What is the difference between a thyristor and a MOSFET based R/R?

Metal Oxide Semiconductor makes MOS, and Field Effect Transistor makes FET... that is, both the name of the semiconductor type (semiconductor = diode, very loosely) and the actual type of circuit...

The "diodes" that are used for switching to current to ground on and off are either thyristors, basically a diode with a third leg that acts as a switch, or MOSFETS, which are transistors functioning in a similar capacity.

The switches in the Regulator part are either type, but they both do the same thing... The rapidly turn on and off, short circuiting power to ground to keep voltage constant... That's called "Shunting", and almost every type of bike regulator used now is made this way...

Every time you short circuit something, it creates heat, just from the short circuit... That's the same for both types... But, the difference is in how you switch.

On a thyristor based R/R the most heat isn't from the short circuit, it's from the switching... A thyristor is basically a diode with a separate leg, acting as a switch... But the switch has a delay... The thyristor relies on the current flowing through it, to keep it open...

Basically the switch opens the door a crack, and then waits for the current to crash into the door, slamming it open... Closing it is similar... You slowly, slowly push the door closed enough until the current looses power and can't hold the door open, slamming it shut...

As a result, the thyristor is horribly inexact and inefficient... It takes time to switch, and it creates huge amounts of heat while doing it...

The MOSFET is a bit more intelligent... It doesn't rely on the current for opening the door, and it doesn't try to close it slowly... Instead the switch is really a switch... Switching it on means it starts to conduct fast, and switching it off means it stops almost as fast... That creates a lot less heat, and makes it more exact... A lot more exact...

It's a very good upgrade, it's infinitely more robust than the crappy OEM one... And since it's specified for 50W, it's not working hard too keep up with demand, and that makes it age slower... So it will happily keep working twice the time an OEM one or a cheap OEM copy will... A MOSFET based R/R should never, ever fail from heat.

As a result of this, a typical thyristor based R/R will produce 13.5-14.5V if it's healthy... And in semi healthy condition usually 13.2-14.8V... But depending on the temperature in the R/R, RPM and how fast the RPM changes it will swing wildly between these values at random...

A MOSFET based R/R in new condition usually provides 13.5-14.5V, and in semi healthy condition (which takes about 20-30 times longer than the thyristor's to age into) the same 13.2-14.8V...

But... And that's a pretty important but... The MOSFET R/R tends to go towards middle voltage at just off idle RPM, and then towards lower voltage at high RPM, with only small peaks towards higher voltage usually when the RPM's change... Also the swings are slower, more controlled...

This means that as long as the battery is in good condition it has no problems coping with a semi reliable R/R of either type... But a thyristor based R/R will age it sooner, and ages itself sooner... And then you get problems...

A MOSFET based R/R keeps the battery lasting longer, keeps the voltage more constant, which is good for the ECU/CDI, the electronics in the gauges, the fuses and also keeps the light bulbs in your headlight happy since it likes just above 14V to make peak light output (provided you have decent wiring to it)...

Both types will make fireworks and smoke when they battery boils over if a diode in the Rectifier decides to go wide open, and both will stop charging the battery if it fuses... But a MOSFET Regulator takes a very, very long time to go "bad" enough to create the heat needed for damaging the Rectifier diodes... Corroded connectors are obviously something that affects both equally in terms of resistance/heat...

Again, the effect and importance of a good regulator becomes even more apparent when the stator's output is increased, and with 100 more watts available, a more efficient regulator that runs cooler is a plus . . .:laugh:

POWERHOUSE always has mosfet regulators in stock for the Gen 1, and Gen 2, including the new style regulator used in the 2013+ Busas. They are only $155 and well worth it.

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