Poor boy idle voltage


Information and questions on GL1200 Goldwings (1984-1987)
  • Sponsored Links
guido04@comcast.net
Posts: 21
Joined: Tue Sep 24, 2013 7:03 pm
Location: Silverdale, WA
Motorcycle: 1986 GL1200A Aspencade, 2002 GL1800

Poor boy idle voltage

Postby guido04@comcast.net » Thu Mar 27, 2014 10:02 pm



I know people have posted time and again about the poor boy conversion, however I am not finding what I am looking for. I already have the poor boy conversion done, however my idle volt is still around 11.4 volts and does not get above 13 volts until around 1500 rpm's. A lot of people I have seen post say above 13 volts at idle. What should I actually expect with the poor boy conversion at idle??? And if I am not where I need to be, what might be the issue?



User avatar
RoadRogue
Posts: 1915
Joined: Sun Jun 06, 2010 10:51 pm
Location: Castlegar BC, Canada
Motorcycle: 1997 1500SE

Re: Poor boy idle voltage

Postby RoadRogue » Thu Mar 27, 2014 11:29 pm

What size pullies are you using? What alternator are you using? Did you hook up the sensing terminal? Oh so many questions..... 8-)
Ride safe, Todd
Over night campers welcome

guido04@comcast.net
Posts: 21
Joined: Tue Sep 24, 2013 7:03 pm
Location: Silverdale, WA
Motorcycle: 1986 GL1200A Aspencade, 2002 GL1800

Re: Poor boy idle voltage

Postby guido04@comcast.net » Fri Mar 28, 2014 8:14 am

I am not sure of the pulley size as I did not do the install myself due to lack of equipment. It is a geo metro alternator, however the pulley I know was an issue. They stopped making the original pulley, then the shop ordered the wrong size twice. Not sure what the pulley ended up at, I need to pull the bike apart this weekend. As far as sensing terminal, are you referring to the volt meter? I have one installed on my bike

User avatar
WingAdmin
Site Admin
Posts: 17046
Joined: Fri Oct 03, 2008 4:16 pm
Location: Strongsville, OH
Motorcycle: 2000 GL1500 SE
1982 GL1100A Aspencade (sold)
1989 PC800 (wife's!)
1998 XV250 Virago (sold)
2007 Aspen Sentry Trailer

Re: Poor boy idle voltage

Postby WingAdmin » Fri Mar 28, 2014 9:45 am

guido04@comcast.net wrote:I am not sure of the pulley size as I did not do the install myself due to lack of equipment. It is a geo metro alternator, however the pulley I know was an issue. They stopped making the original pulley, then the shop ordered the wrong size twice. Not sure what the pulley ended up at, I need to pull the bike apart this weekend. As far as sensing terminal, are you referring to the volt meter? I have one installed on my bike


The sensing terminal is on the alternator and is used to monitor the voltage of the battery, so the regulator inside the alternator knows how much power to generate.

User avatar
RoadRogue
Posts: 1915
Joined: Sun Jun 06, 2010 10:51 pm
Location: Castlegar BC, Canada
Motorcycle: 1997 1500SE

Re: Poor boy idle voltage

Postby RoadRogue » Fri Mar 28, 2014 1:30 pm

Here is an example of the terminals on the back of most alternators 8-)
Ride safe, Todd
Over night campers welcome

guido04@comcast.net
Posts: 21
Joined: Tue Sep 24, 2013 7:03 pm
Location: Silverdale, WA
Motorcycle: 1986 GL1200A Aspencade, 2002 GL1800

Re: Poor boy idle voltage

Postby guido04@comcast.net » Sun Mar 30, 2014 2:09 pm

Ok, so there is no wire from the sensing terminal. When it was installed they ran the main line to the battery, then ran a line from the ignition terminal to a spare fuse block that I have. I can completely disconnect the wire from the ignition and it does absolutely nothing to my voltage

User avatar
RoadRogue
Posts: 1915
Joined: Sun Jun 06, 2010 10:51 pm
Location: Castlegar BC, Canada
Motorcycle: 1997 1500SE

Re: Poor boy idle voltage

Postby RoadRogue » Sun Mar 30, 2014 5:22 pm

guido04@comcast.net wrote:Ok, so there is no wire from the sensing terminal. When it was installed they ran the main line to the battery, then ran a line from the ignition terminal to a spare fuse block that I have. I can completely disconnect the wire from the ignition and it does absolutely nothing to my voltage


The B terminal should have a heavy 10ga. wire running to a fuse just before your battery and then to the + post of the battery. The I terminal should have a 14ga. wire running to a switched terminal ( like the one on your spare fuse block). The sensing terminal should also be 14ga. and run to either the positive battery terminal or to a switched acc terminal as close to the battery as possible.

You didnt state the size of the pullies yet ,but if you have anything better than a 1:1 ratio you should be ok. 2:1 works very well. You may need to have the alternator tested, you didnt say if it was new or used. Is the old reg/rec unplugged? So many questions but fear not we will get you through this 8-)
Ride safe, Todd
Over night campers welcome

guido04@comcast.net
Posts: 21
Joined: Tue Sep 24, 2013 7:03 pm
Location: Silverdale, WA
Motorcycle: 1986 GL1200A Aspencade, 2002 GL1800

Re: Poor boy idle voltage

Postby guido04@comcast.net » Sun Mar 30, 2014 5:57 pm

There is no wire running from the sensing line. I tried removing the line running from the ignition to the alternator and ran it from the sensing line on the alternator to the fuse box but it did not do anything. I am not sure what size the pullies are. Why does the size matter? If the size was wrong it would not rotate, right? Alternator is brand new geo metro alternator. The stator wires are cut so the rectifier should not be connected. I am going to replace the battery just to eliminate that aspect of it.

User avatar
RoadRogue
Posts: 1915
Joined: Sun Jun 06, 2010 10:51 pm
Location: Castlegar BC, Canada
Motorcycle: 1997 1500SE

Re: Poor boy idle voltage

Postby RoadRogue » Mon Mar 31, 2014 12:26 am

guido04@comcast.net wrote:There is no wire running from the sensing line. I tried removing the line running from the ignition to the alternator and ran it from the sensing line on the alternator to the fuse box but it did not do anything. I am not sure what size the pullies are. Why does the size matter? If the size was wrong it would not rotate, right? Alternator is brand new geo metro alternator. The stator wires are cut so the rectifier should not be connected. I am going to replace the battery just to eliminate that aspect of it.



You need to run all three wires at the same time B terminal ,I terminal and the S terminal for it to operate properly. Pulley size is the key to success if you only have a 1:1 ratio then at idle the alternator is spinning too slowly to make enough volts to charge your battery. Take a look at the pullies on your car or truck, the crank pulley is at least 4 inches in diameter while the alternator is about 2 inches. This way the alternotor is spinning 2X as fast as the crankshaft. If you are only getting 13.5+ volts above 1500 rpm and you do have a small crank pulley or the same size as your alt pulley at idle each 9s spinning somewhere under 1000rpm and thats not enough to charge the battery. Now if your crank pulley is say 4 inches and your alt pully is 2 inches , at the same idle speed of say 1000 rpm for example the alternator is now spinning at 2000rpm. That is fast enough to charge the battery at idle.
Please try unplugging the old reg/rec, you dont need it connected to the battery anymore. 8-)
Ride safe, Todd
Over night campers welcome

User avatar
littlebeaver
Posts: 4420
Joined: Mon Sep 21, 2009 6:11 pm
Location: Kansas City, Kansas
Motorcycle: 1981 gl 1100 I , 79 Yamaha XS11
Special, 82 Kawa 750 CSR, 82 Kawa 750 LTD, 03 Kawa Nomad 1500, 99 Kawa Voyager 1200

Re: Poor boy idle voltage

Postby littlebeaver » Tue Apr 08, 2014 12:14 am

that's what mine is 4" to 2 " and I get 14volts at 950 rpm just like an automobile... Life is good...Never had a issue with this set up.. the pulley size is what makes the difference,, I had a 3" on it for a while and it was 2" on the alt., boo it wasn't what I wanted,,I wanted a full 14 volts at idle so it could pull everything mighty fine sitting at a light... :shock: :lol:

guido04@comcast.net
Posts: 21
Joined: Tue Sep 24, 2013 7:03 pm
Location: Silverdale, WA
Motorcycle: 1986 GL1200A Aspencade, 2002 GL1800

Re: Poor boy idle voltage

Postby guido04@comcast.net » Tue Apr 08, 2014 8:18 am

Just replaced all my running lights with LED's so that should help. Just having a hard time ripping it apart because I try to use it as a daily rider and the weather is actually nice.

guido04@comcast.net
Posts: 21
Joined: Tue Sep 24, 2013 7:03 pm
Location: Silverdale, WA
Motorcycle: 1986 GL1200A Aspencade, 2002 GL1800

Re: Poor boy idle voltage

Postby guido04@comcast.net » Sat Feb 21, 2015 8:19 pm

Sorry I have taken so long to reply, I was deployed. So I finally started working on the bike. Battery is good, 12.5-13V when off, 14.52V when above 1500 RPM. Added a wire from the 'S' terminal to positive on battery so I now have wires running from the B, S, I terminals and no change in idle voltage. The alternator pulley is 2.5" and the main appears to be a 3.5-4". Reg/ rec is disconnected. What is my next step, pull the alternator, or try a bigger pulley ratio?

User avatar
littlebeaver
Posts: 4420
Joined: Mon Sep 21, 2009 6:11 pm
Location: Kansas City, Kansas
Motorcycle: 1981 gl 1100 I , 79 Yamaha XS11
Special, 82 Kawa 750 CSR, 82 Kawa 750 LTD, 03 Kawa Nomad 1500, 99 Kawa Voyager 1200

Re: Poor boy idle voltage

Postby littlebeaver » Sat Feb 21, 2015 9:32 pm

Are you saying that there is no change from idle volts to wide open,, should not go over 15 volts,,, should stay in the 14 volt area with this ratio... put a volt meter or multimeter at the battery and read it as you accelerate and see if the volts change, should go from lower 14 volts to a higher 14 volts...What did you hook S wire to...? .. I got a plugin from the junk yard.
when I turn stuff on full blast like the stereo and bright lights the volts at idle may drop a little below 14 volts in the upper 13's
Last edited by littlebeaver on Sun Feb 22, 2015 1:51 am, edited 3 times in total.

guido04@comcast.net
Posts: 21
Joined: Tue Sep 24, 2013 7:03 pm
Location: Silverdale, WA
Motorcycle: 1986 GL1200A Aspencade, 2002 GL1800

Re: Poor boy idle voltage

Postby guido04@comcast.net » Sat Feb 21, 2015 10:03 pm

It changes from about 12.20 at idle (1000-1050 RPM) to 14.52V at about 1500 RPM and higher at the battery terminals. If I turn on all my lights and radio, drops about .5-.7 volts when revved. The S terminal is going to the positive terminal on the battery. I do not have any wire running from the L terminal. What did you run that to?

User avatar
littlebeaver
Posts: 4420
Joined: Mon Sep 21, 2009 6:11 pm
Location: Kansas City, Kansas
Motorcycle: 1981 gl 1100 I , 79 Yamaha XS11
Special, 82 Kawa 750 CSR, 82 Kawa 750 LTD, 03 Kawa Nomad 1500, 99 Kawa Voyager 1200

Re: Poor boy idle voltage

Postby littlebeaver » Sat Feb 21, 2015 10:55 pm

L is to ground,, gotta go to frame or negative, I'm pretty sure that's your problem.... I went to frame .... (IG) goes to ignition wire Black wire on my 1100 at the RR plug black wire with a spade connector ... some guys go to the fuse box terminal, I'm guessing the Positive one for (IG) 99% sure of that.. .. You have to hook up L wire to ground though.. If you don't have a plug like this one in the photo, then hook up the S like you have it.. Make these changes and you will be charging much higher just you wait and see and thank you for your service.... You are so close to having this right it's not even funny.... :lol:

User avatar
littlebeaver
Posts: 4420
Joined: Mon Sep 21, 2009 6:11 pm
Location: Kansas City, Kansas
Motorcycle: 1981 gl 1100 I , 79 Yamaha XS11
Special, 82 Kawa 750 CSR, 82 Kawa 750 LTD, 03 Kawa Nomad 1500, 99 Kawa Voyager 1200

Re: Poor boy idle voltage

Postby littlebeaver » Sun Feb 22, 2015 5:41 am

Scratch what I said about the L wire above,,, that's just for the warning light... I'm losing it man...It's been so long since I have wired this I forgot... S goes to positive on battery , IG goes to positive terminal at fuse box, and B goes to positive at battery.. the alt, is grounded.....
Last edited by littlebeaver on Sun Feb 22, 2015 6:43 am, edited 1 time in total.

User avatar
RoadRogue
Posts: 1915
Joined: Sun Jun 06, 2010 10:51 pm
Location: Castlegar BC, Canada
Motorcycle: 1997 1500SE

Re: Poor boy idle voltage

Postby RoadRogue » Sun Feb 22, 2015 3:59 pm

what are you using for a volt meter and where are you reading it from? If you are using the one on the dash of your bike, it probably isnt very accurate. You should use a quality DVM at the battery terminals. If you still have low readings then pull the alternator and have it tested. 8-)
Ride safe, Todd
Over night campers welcome

guido04@comcast.net
Posts: 21
Joined: Tue Sep 24, 2013 7:03 pm
Location: Silverdale, WA
Motorcycle: 1986 GL1200A Aspencade, 2002 GL1800

Re: Poor boy idle voltage

Postby guido04@comcast.net » Mon Feb 23, 2015 9:32 am

I am using a multimeter at the battery posts. If I rev the engine, I hit 14.5 volts at the battery above 1500 RPM. Doesn't that mean that the alternator is working and producing enough output? And if that is the case would it then just be a problem with the sensing line not automatically bumping the alternator output?

User avatar
littlebeaver
Posts: 4420
Joined: Mon Sep 21, 2009 6:11 pm
Location: Kansas City, Kansas
Motorcycle: 1981 gl 1100 I , 79 Yamaha XS11
Special, 82 Kawa 750 CSR, 82 Kawa 750 LTD, 03 Kawa Nomad 1500, 99 Kawa Voyager 1200

Re: Poor boy idle voltage

Postby littlebeaver » Mon Feb 23, 2015 12:48 pm

That would be my guess... It's reading a bit low at idle for that ratio.....

guido04@comcast.net
Posts: 21
Joined: Tue Sep 24, 2013 7:03 pm
Location: Silverdale, WA
Motorcycle: 1986 GL1200A Aspencade, 2002 GL1800

Re: Poor boy idle voltage

Postby guido04@comcast.net » Sun Mar 01, 2015 7:38 pm

Ok, so I have narrowed down the issue, I am pretty sure it is the pulley ratio. I have a 4" pulley to a 2.5" pulley, which works at travel speed, but not at idle. From what I have researched, the average ratio for a car tends to be a 3 to 1 ratio. Littlebeaver, where did you get your 2" pulley from, and do you have a part number? Thanks for the help

User avatar
littlebeaver
Posts: 4420
Joined: Mon Sep 21, 2009 6:11 pm
Location: Kansas City, Kansas
Motorcycle: 1981 gl 1100 I , 79 Yamaha XS11
Special, 82 Kawa 750 CSR, 82 Kawa 750 LTD, 03 Kawa Nomad 1500, 99 Kawa Voyager 1200

Re: Poor boy idle voltage

Postby littlebeaver » Sun Mar 01, 2015 9:32 pm

First, what is your idle speed? Is it 950 to 1000 rpm? it may be too low...if it's not here and these numbers its too low... It's not the ratio... It shouldn't get that low at that ratio, it should be at least in the lower 13's...that's all I can think of to make it charge that low at idle....Make sure the belt is tight enough, that could effect it too... I think I got it at an alternator shop in San Antonio,, I'm in KC now...Your ratio is dandy, are you using a v belt or a serpentine? It's charging it when your rpm's go up... It has to be a loose belt..

User avatar
littlebeaver
Posts: 4420
Joined: Mon Sep 21, 2009 6:11 pm
Location: Kansas City, Kansas
Motorcycle: 1981 gl 1100 I , 79 Yamaha XS11
Special, 82 Kawa 750 CSR, 82 Kawa 750 LTD, 03 Kawa Nomad 1500, 99 Kawa Voyager 1200

Re: Poor boy idle voltage

Postby littlebeaver » Wed Mar 04, 2015 2:43 pm

I just realized you have a 1200, check the idle speed information for the 1200's, The speed I posted is for my 1100...Sorry about that...

guido04@comcast.net
Posts: 21
Joined: Tue Sep 24, 2013 7:03 pm
Location: Silverdale, WA
Motorcycle: 1986 GL1200A Aspencade, 2002 GL1800

Re: Poor boy idle voltage

Postby guido04@comcast.net » Fri Mar 06, 2015 3:44 pm

Idle speed is about 950-1000 rpm. I calculated that at idle my alternator should be rotating at 1600 rpm. Trying to find info on whether that is high enough to charge or not. I do not think my belt is slipping.

User avatar
littlebeaver
Posts: 4420
Joined: Mon Sep 21, 2009 6:11 pm
Location: Kansas City, Kansas
Motorcycle: 1981 gl 1100 I , 79 Yamaha XS11
Special, 82 Kawa 750 CSR, 82 Kawa 750 LTD, 03 Kawa Nomad 1500, 99 Kawa Voyager 1200

Re: Poor boy idle voltage

Postby littlebeaver » Fri Mar 06, 2015 5:10 pm

Take that alternator off and go have it tested...I think the regulator is messed up.....that's all I can figure man...

User avatar
littlebeaver
Posts: 4420
Joined: Mon Sep 21, 2009 6:11 pm
Location: Kansas City, Kansas
Motorcycle: 1981 gl 1100 I , 79 Yamaha XS11
Special, 82 Kawa 750 CSR, 82 Kawa 750 LTD, 03 Kawa Nomad 1500, 99 Kawa Voyager 1200

Re: Poor boy idle voltage

Postby littlebeaver » Fri Mar 06, 2015 5:53 pm



My pulley on the alternator is 2 1/8 " and 4" at the crank and this is what I get... should not be that low on yours...




Return to “GL1200 Information & Questions”




Who is online

Users browsing this forum: No registered users and 1 guest