Alternator swap 1998 model

[savvy]

Hi folks, having sorted my headlights, Fazer400, I put my multi meter on and noticed the charge was 14.5v at approx 3000 rpm.
 Looking through the Haynes the 98 model is rated at 12v.
 Is it a straight swap to do from a 2002/3 model as that would seem to be the only solution?
Cheers

[His Dudeness]

Maybe I've read your question wrong but 14.5V sounds right for 3000 RPM. It's a 12V system but the voltage goes up as you rev the bike to charge the battery

[savvy]

Hi, I was just going off this in the Fazer service manual,



Charging system:
Type
Model/manufacturer
Standard output
Stator coil resistance
A.C. magneto
F4T359/MITSUBISHI
12 V 18 A at 5,000 r/min
0.36
0.44 W at 20C/W-W


I was thinking same as you before checking Haynes which corresponds to the same info. I was just wondering if later alternators fit. Quite a few bits have been done on this bike before I got it.
 Thanks

[His Dudeness]

That's just a manufacturer's spec for that "F4T359/MITSUBISHI magneto". Have a look in your Haynes at the testing the charging system section. It'll say something like the battery should be around 12.5V with the bike switched off and around the 14.3V at 5000RPM like you're getting. There's no problem with your bike. If it was overcharging and putting out say 17V at idle it'd would probably be the regulator/rectifier that was at fault not the alternator.

[savvy]

Hi. many thanks will get on to checking it all out.