Charges better at idle?

[byggd]

I read several threads on charging but none with this issue.

At idle by bike charges at about 13.4~13.7 but when I bring the RPMs up it starts dropping and stabilizes at about 12.4. I pulled the battery out and cleaned all the connection at the battery but still get the same results.

Any ideas?

PS:

The factory manual states that regulated voltage should be 14-15 V at 5,000 RPM.

It has instructions on how to test the voltage regulator/rectifier and I found that easily enough.

But....

It says to test the stator "remove the right side cover and fuel pump stay"?? Are they referring to the right chrome cover? Only thing behind it is the tool kit. I don't see the 3P connector used to test the stator.

-Don

[Scrapdog2grand]

Originally Posted by byggd

It says to test the stator "remove the right side cover and fuel pump stay"?? Are they referring to the right chrome cover? Only thing behind it is the tool kit. I don't see the 3P connector used to test the stator.

-Don

Thats the one you need to find, may be your problem.
follow the wires out of the left side cover.

[trabb47]

+1 follow the 3 wires to a plug. Pull plug apart and check for burned connectors This is the weak spot in the system. Cut the plug off and solder the wires. Better known as the 3 yellow wire fix. I talk from my own experience. Easy and cheap fix.

[hypostang]

On my 1990, the three wire plug was behind the left side cover just below the ignition switch and a tad bit towards the rear of the bike .Hope that helps

[rrounds]

Most of the 1100 shadows do that, mine dropped down to 12.6v as the rpm's went up.
Here is what every bike that takes a R/R should have
Roadstercycle-Index
The MOSFET R/R got me 13.9 at idle and 14.2 at 4000 rpm. And when your volts are up at 14.2 you get a much brighter headlight.
Take a look at how volts or the lack of them change the lumens of a bulb(this is off of Daniel Stern Lighting).

The drop in light output is not linear, it is exponential with the power 3.4. For example, let's consider a 9006 low beam bulb rated 1000 lumens at 12.8 Volts and plug in different voltages:

10.5V - 510 lumens
11.0V - 597 lumens
11.5V - 695 lumens
12.0V - 803 lumens
12.5V - 923 lumens
12.8V - 1000 lumens ←Rated output voltage
13.0V - 1054 lumens
13.5V - 1198 lumens
14.0V - 1356 lumens ←Rated life voltage
14.5V - 1528 lumens

So with 14+ volts the head light will be very bright compared to the same bulb with only 12.8 or less volts.

ROD

[byggd]

Thanks for the replies. I'll check on the left side for the 3P connector.

So the factory manual stating that regulated voltage should be 14-15 V at 5,000 RPM is incorrect and for the most part this is normal? I'm hoping not to need a $130 R/R to fix this.

[verdeva]

I hope that it is normal for your bike; on mine the same symptoms was the stator going bad. I would do the electrosport tests jsut to be sure before I soldered the yellow wires.

[PainterD]

Got a used Mosfet type voltage regulator off Ebay (Yamaha R1) for cheap and took care of my problem and also saved the stator from going bad also. The main reason the stators go out (start to burn connections) is because of the poor regulator Hondas use. They are junk.
Also, if you do go with a Mosfet regulator, change all the charging curcuit wires to 10 gauge wire to handle the added power. Problem solved!

[PainterD]

Got a used Mosfet type voltage regulator off Ebay (Yamaha R1) for cheap and took care of my problem and also saved the stator from going bad also. The main reason the stators go out (start to burn connections) is because of the poor regulator Hondas use. They are junk.
Also, if you do go with a Mosfet regulator, change all the charging curcuit wires to 10 gauge wire to handle the added power. Problem solved!

[damian.garcia83]

Originally Posted by PainterD

Got a used Mosfet type voltage regulator off Ebay (Yamaha R1) for cheap and took care of my problem and also saved the stator from going bad also. The main reason the stators go out (start to burn connections) is because of the poor regulator Hondas use. They are junk.
Also, if you do go with a Mosfet regulator, change all the charging curcuit wires to 10 gauge wire to handle the added power. Problem solved!

Having same problem as OP, so I thought I would resurrect this thread for its relevance.

When you say change all the charging wires to 10-gauge, specifically what wires do you mean? Those coming from the R/R to meet with the wires from the stator? Wouldn't you have to rewire the stator to do that? BTW, I have already soldered/heatshrinked the wires together from the stator to R/R. So what I am thinking is I will have to redo the complete harness between them, is that what you mean?

And do you know the year of the stator you got from an R1?

Damian