Strange Electrical Readings

[Guest darved]

Hi guys,

I bought a 97 VFR 750 a few weeks ago. Have ridden about 300 miles on it and the last time I rode I stalled it at my front door and it hasn't started since. My flat mate is a mechanic so I got him to help do a few tests of the electrical system with the help of the information from the haynes manual

At idle it was running at around 12.0V and at 5000rpm at around 12.5V

With the lights on, it went down to around 11.5V

On inspection, the plug that connects to the rectifier was all brown and melted so we decided to change the rectifier - and use spades instead of the plug. I bought a GSXR r/r based on the feedback from this forum:

http://www.vfrdiscussion.com/forum/index.php?showtopic=42900

Anyway, after connecting up the new r/r, we started it up and performed the same tests.

At idle it now runs at around 10.0V and at 5000 around 9.5V.

Plugged the old r/r back in and its the same - 10V at idle, 9.5V at 5000.

Does anyone have any ideas on what the problem could be?

I'm running out of summer time

[Guest]

What is the input to the r/r from the Alternator? Maybe that is part of the problem?

[Tightwad]

I sounds like you are getting no charging, and the battery is dying down on you. Charge the battery, and check the 3 yellow connections, you should be able to measure A/C voltage in the 55-65 volt range at 5K rpm. Also check the Starter Relay plug, it could be burned up on the Red/White wire, causing the charging system to not provide any power to the battery.

Probably half of the people who have purchased the VFRness for the 90-97 model bikes have had Starter Relay connection problems, which is why the VFRness includes a repair kit for that.

[Guest]

Thanks very much for the replies. The battery is dead flat so I'm going to get a charger and charge it and then I'll perform the tests mentioned. I'll post the results as soon as I have them. Thanks for the help.