Rectifier question
 

This question may need to be asked on the VFR board but I'm not a member so I will ask here.
One of my riding buddies has a 97 VFR and he had rectifier problems so he put the Gixxer rectifier on it. He is an auot mechanic so he knows something about electrical and had no trouble installing it. When we checked the charging rate with a multi-meter at idle it is only putting 12.7 volts and at 4 to 6 thousand rpm it is putting out 15.7 volts. These charging rates don't sound right to me, not enough at idle and too much at road speed. It seems he will end up with an overcharged battery if riding any long distance.
I checked my SH as a comparison and it is putting out 14.55 at idle and 14.04 at 4000 rpm. which is about the same as my ATV and my Aprilia.

Does anyone know if he is going to have a problem with the charging rate he is getting? I'm no expert , but I think something is wrong.

What do you think?

Re: Rectifier question
 

I think you're right. His vfr should have a charging rate in the 14's to 15. If he does'nt want to pay the big$$ from Honda, Electrex in CA. has them cheaper. And they are gauranteed for 6 mo. or 1 year.

Sounds right to me. Full charging happens over 3,500 rpms.

Re: Rectifier question
 

IIRC, the manual calls anything between 13.5-15.5 @ 5K rpm as normal. Given meter errors of .2 to .3 volts, that gixxer r/r might be fine but.... that idle measurement is too low. Has the stator and connection (one between tank/battery) been checked out as good?

My gixxer r/r puts out a steady 13.8 to 14.2 from idle to redline. I have a voltmeter wired in on the dash. I got a used stator cover off ebay to replace my badly rashed one and it came with the stator still bolted on (SCORE!). It delivers the same results.

12.7v is way too low for running conditions. Sounds like a wire was missed or incorrectly connected. Ideally you should be looking at around 14.5v across the battery with the engine running.

According to the manual, it is working correctly. If the rectifier or the charging coil is bad, it will charge at no more than 2/3rds of the specified voltage. Remember, there are three charging circuits that add up to about 15 volts. So a bad charging system can't achieve over 10 volts.

The idle measurement is not a charging voltage because idle is too slow for much charging. It is the battery voltage.

Re: Rectifier question
 

Thanks for the replies. I have been out of town and just got back today so I will send a link to this thread to the guy that owns the VFR.

jschmidt,
If the idle is to low to get a charging reading how come all wy other bikes and my ATV charge over 14 volts at idle?

Re: Rectifier question
 

Bigger stator.