[dentalboy]

I have a burgman 400 k1. I have just replaced the rectifier as the old one burnt out. It was a 5hour job as i have no manual to tell me how to do this :cussing: but i did it. So has anyone else had this happen to them. I bought a second hand one for £35. But is there any reason for this to fail in the first place?

 

[Dave_J]

I am not sure about the 2001 400's but in the later years the rectifiers were junk. Suzuki went with the cheapest units available, lowest bidder thing. The commen repair is to replace it with a MOSFET unit as it works differently and so much better. Do a search on here and you will find links on how to do it. It is not a plug in unit, the wiring and mounting holes must be modified some.

 

[GK13]

What's a rectifier, and what does it do?

 

[Dave_J]

A rectifier is a device that takes AC voltage and converts it to DC. It does it using diodes set up in a bridge system. Its a bit hard to explain but the + of the AC flows thru one diode faced one way but not thru its twin faced the other way. There is usaly 4 diodes in a simple bridge so when the AC switches poles, the other sides diodes let the + flow, keeping the + pulse from both sides of the cycle going to the DC's + pole. Better Bridge circuits have many pairs of diodes and capacitors and so on.....

 

[Dave_J]

In the case of our bikes Rectifier, it is a combo of rectifier and voltage regulator. The stator (alternator) of our bikes (650) puts out 80 volts of AC. That AC goes thru the rectifier and comes out as 80 volts DC. Then the regulator clips it down to the required 12 volts DC. But if you were to put a speaker on it it would make a BERRRRRRRRR noise, that is "Ripple Pulse" DC and electronics do not like that so the battery mellows out the pulse by being a steady 12 volts DC.

Hope I have not left anything out. Did I lose anyone???

 

[dentalboy]

I was with you all the way, and put better than i would have! The MOSFET unit you mention seems to rarer than hens teeth in the UK. If this unit burns out i may even try a Chinese one.[or not]

 

[Mel46]

In case anyone didn't get that, this pdf file should help.
http://www.irf.com/technical-info/appnotes/mosfet.pdf

 

[GK13]

thanks for the explanation. what makes it go out on the burgman? should i try to check it or anything?

 

[Dave_J]

GK, the early year units I know nothing about the stats but I think 2007 and up there may be a recall on the 400's. There has been a rash of failures on 650's too but no recall.

The cause, IMHO, is PI$$PORE materials, due to low bidder suppliers. The fast fix is a factory replacement. The better fix is to spend more money and get a retro-fit MOSFET unit from a Yamaha or such. You would need to cut your plug off your old unit and splice it onto the new MOSFET unit. These splices must be real good. I'd recommend water tight "Posi-Tap" connectors rated for the amps.