1982 Yamaha XZ400

[Greenhonnet]

Kiaora kotoe katua. Here I bought this old beast 1987 Yamaha XZ400 yesterday. The last owner trying to start the bike for me using a jumper lead that hooked up to her phone. It keep blowing up the 5 amp fuses until she has ran out in the pack. We couldn't determine what"s went wrong as the voltmeter of the battery has shown the voltage of 12.67v. With this amount of voltages it should start and crank up the motor just right without blowing the fuses. I consulted the mechanic and he reckon its the rectifier or voltage regulator that played up. Written to a part specialist, he reckon it might be the stator that deliver too much power that keep blowing the CDI. Any expertise advices about the issue of this bike?

[jellywrestler]

Electrical issues generally are not bike specific, and 90% of the time earth related.

If you have a voltmeter you should be able to test those parts to narrow down which is at fault, or if they are in fact both fine and it's something else, with either some Googling on how to do it, or pulling them off and taking them to your local auto sparky and watching them do it so you know for next time.

the XZ's were notorious for electrical issues and how if there's two parts to the main wiring, positive and earth do 90% of issues only happen on one of these two?

[Greenhonnet]

Kiaora kotoa katoa,

Am not too sure how the short circuit of the wire happened that leading to the blown up of several fuses. But I am very the same page as the previous respondent, 90% of short circuit happened because of the earth wiring. It was strange thing that before it happened we almost there to jump started the bike with the usb link jumper starter. Guess the sparkie will find out the main causes.

[Bonez]

As Spyda said these were prone to charging/reg/rect issues. szxo were early 80s Susukis. And some models from other manufactures.

As I said in the other thread get hold of a XZ550 manual, in pdf format it'll give resistance readings for the charging components as the 550 shared a lot of tyhe same components as the 400.

A lot of ex Jappanese market came over to NZ and Aust. Lilke your model, GL400s, GB400s, CB 650 Customs and a few other models from various manufaters.

[F5 Dave]

One of the two is an electrician, I'll leave it to you to guess which one is asking the critical question,.

For the love of satan please dont spend money on it paying someone to fix it.

Good money after bad is just money lost.