Alternator bump??

[hop along]

To start, Thank You to this great group and wealth of knowledge.  I've picked up a LOT of knowledge about my 2003 magna here and put it to good use.  My favorourite was the Valk tank conversion, since I put on about 15,000 miles a year.

SO, I live in Ohio and want to lengthen the comfortable riding season by bumping up the alternator output (more heated gear please, especially for the woman on back).  There are several options/questions/things I don't know.  I have found on the forum that stock output is 374 watt, at 5000rpm.  I max this out with a heated jacket and PIAA lights (even with LED replacements on instrument lights, signals and brake light).  Yes, I do ride with both the jacket and lights on high at night.

?Did Honda make other engines with similar stator but with a larger output (for an easy swap?)

?Has anyone tried an aftermarket stator, for example those available from Rick's Powersports, or Esport?

?Local rewinding of the stator?

Since it's January, that means time to get the tools out and play...

Best,
Hop Along

[Chad in Michigan]

electrosport offers a higher output stator (like an extra 100w output) if i remember right. try www.electrosport.com (i think)

[hootmon]

First - Welcome Hop to the Forum from Floriduh...

Be careful with a re-wind.. Honda tried this on the GL1200 to up the amps from the GL1000. But to get the extra winding in, they made the wire thinner.. Yep you guessed it.. They had lots of fried stators as a result..
I think going with something like the electrosport (there are a couple of others) is the best you are going to do. IF you are going to up the stator, then I would go ahead and up the regulator as well. There are Regulators that up the output at that point as well. I'd buy a matched set from the same company.. I would also think about moving the regulator or adding a fan if you are going to up the output as I would think this would also up the heat..
Just do a search on Regulator failures (there are a couple of long threads) and some suggestions on moving the regulator..

Welcome, and keep us updated..

[drkngas]

The spec for the electrosport stator doesnt seem right.  especially since it's called "heavy duty".


This heavy duty stator can be used as a higher output replacement
for the OE stator. Output is about 20% more than the OE stator provides.

Power Output: 247W @ 4000RPM*
*The actual power output varies depending on the configuration
and condition of the charging system. Actual performance is typically
within +/- 5% of this value.

[Sledge Hammer]

Bear in mind that a higher output alternator means more power that must be dissipated in the regulator as heat when the extra load is not present to draw the power. The regulators already suffer from terrible thermal management 00 as in, what imbecile thought the back of the plastic box for the battery, out of the airflow, was a good place to mount a device which needs to shed heat as effectively as possible? You might want to read Lawrence Ragan's posts on temperature measurements on the regulators he has recorded on one of his Magnas. It is pretty convincing evidence that the regulators run way too hot for good reliability of the thyristors used to regulate the voltage, particularly in hot weather. Some of the guys have relocated their regulators to get improved airflow to bring the temperatures down, and I seem to recall that Terry (aka tlram1) has mounted a fan on his bike to cool the regulator.

[hop along]

David,
You're right about the electrosport online spec seeming to be less than desirable, though I have seen on other model forums statements that their online info is incorrect.  I've put in a question regarding this. 
Rick's Motorsports has a stator listed (part 21-130) but I'm waiting to hear if they are able to list a specific output other than a sales rep saying it was 10-15% more than stock.
That is all I've found as yet.  Hootman are you aware of other manufactures?

Also considering a digital readout voltmeter like that made by datel, to ensure all is well-but where on a Magna to mount it I haven't figured out yet....

Best,
Hop Along

[Chad in Michigan]

that stat is wrong on the electrosport from what i've read, too. i think it is a misprint. it does fit other models, maybe check one of those bikes and see if the stat is wrong. also, it bimps down the output from 5k rpm to 4k rpm, which is more in the cruise range. even if the output wattage is very close to the stock output, the rmp's at which the max is put out is in a better,useable range. also, i'm pretty sure anything from ricks is just rebadged electrosport stuff. i don't think they manufacture their own stuff.

[Chad in Michigan]

also, you could get a better battery, that would hold more of a charge. the one i have in my bike is maxed out for cold cranking amps, which is good in the summer heat too. it also has a higer Amp hour rating. it is basicially the same size as the stock battery, but it is slightly taller. it fits underneath my seat, which is a mustang seat, i'm pretty sure it will fit under the stock seat too. this is the one I got last year.
http://www.batterystuff.com/batteries/motorcycle/YTX14H-BS.html

here is a pic of it installed, ignore all the other wiring attached to it the critical point i think would be that it be underneath (or lower than) the metal support behind the battery.

[attachment deleted by admin]

[lragan]

Good suggestion, Chad.  Bigger battery will definitely help with starting issues.

However, if the total load he wants to run is higher than the alternator/regulator/rectifier system can provide, even a bigger battery will eventually run down. 

I agree with Mike that a bigger alternator will probably exacerbate the regulator/rectifier failure issue.  Having said that, it only seems to fail in the summertime, and mostly in hotter climes, so maybe along the northern tier of states a higher power alternator would be a good modification. 

There are a lot of us that would enjoy a bit more electrical power, so I will follow this thread with interest.

[LIMagna]

Chad,

also, you could get a better battery, that would hold more of a charge. the one i have in my bike is maxed out for cold cranking amps, which is good in the summer heat too. it also has a higer Amp hour rating. it is basicially the same size as the stock battery, but it is slightly taller. it fits underneath my seat, which is a mustang seat, i'm pretty sure it will fit under the stock seat too. this is the one I got last year.
http://www.batterystuff.com/batteries/motorcycle/YTX14H-BS.html

here is a pic of it installed, ignore all the other wiring attached to it the critical point i think would be that it be underneath (or lower than) the metal support behind the battery.

Didn't you have this one at one point:

http://www.batterystuff.com/batteries/motorcycle/sYTX12-BS.html

How did it hold up? 

[hootmon]

Hootman are you aware of other manufactures?

I bought a regulator from www.regulatorrectifier.com and I have been happy with it.. It came with longer than stock wire leads which allowed me to relocate the regulator with no problem..


They have several listings for stators and states "This unit has about 20% more higher output capacity than the OEM unit.

Power Output: 247W @ 4000RPM*
*The actual power output varies
However you stated:

I have found on the forum that stock output is 374 watt, at 5000rpm.

So there seems to be a discrepancy between two statements.

Here is their stators listings that I found.
http://www.regulatorrectifier.com/catalog/1994-2003-Honda-VF750C-VF-750C-Magna-Stator
http://www.regulatorrectifier.com/catalog/1994-2003-Honda-VF750C-VF-750C-V45-Magna-Stator

Not sure why they have two listings with two different prices???? Humm

They have several Regulator listings as well. One states:
Re-Designed and Improved OEM Honda VF750C VF 750C Magna Regulator Rectifier has a higher output capacity than the original part, and will not have the problems that you have experienced with your original. Designed to stop overcharging and dissipate extra voltage quickly with 8% better Performance than the original part.
http://www.regulatorrectifier.com/catalog/1994-2003-Honda-VF750C-VF-750C-Magna-Regulator-Rectifier


You stated something about a meter..

I saw this somewhere for a meter. it seems small enough that you could mount it up near the instrument cluster somewhere.. Search for voltage meter and the part number listed in the photo and you should be able to find it..

I agree with Mike that a bigger alternator will probably exacerbate the regulator/rectifier failure issue.  Having said that, it only seems to fail in the summertime, and mostly in hotter climes, so maybe along the northern tier of states a higher power alternator would be a good modification. 

Hey - I suggested that too.. 
It would also seem by statistics that the regulator issues seems to be a 2000 and earlier problem..

I'd still match the stator & Regulator from one company.. 

[Chad in Michigan]

Chad,

also, you could get a better battery, that would hold more of a charge. the one i have in my bike is maxed out for cold cranking amps, which is good in the summer heat too. it also has a higer Amp hour rating. it is basicially the same size as the stock battery, but it is slightly taller. it fits underneath my seat, which is a mustang seat, i'm pretty sure it will fit under the stock seat too. this is the one I got last year.
http://www.batterystuff.com/batteries/motorcycle/YTX14H-BS.html

here is a pic of it installed, ignore all the other wiring attached to it the critical point i think would be that it be underneath (or lower than) the metal support behind the battery.

Didn't you have this one at one point:

http://www.batterystuff.com/batteries/motorcycle/sYTX12-BS.html

How did it hold up? 

No, that is the one I found that would be a direct replacement for the stock battery, in physical size, but i think it does offer a little more than the stock battery, plus it is a sealed gel-type battery i think. I wanted something with more cold cranking amps so i searched batteries by their physical size that would fit in that space and then looked for the max CCA that I could get with the most Ah rating, and that seems to be the one.  When searching initially that is the one I was going to get.

[Chad in Michigan]

To start, Thank You to this great group and wealth of knowledge.  I've picked up a LOT of knowledge about my 2003 magna here and put it to good use.  My favorourite was the Valk tank conversion, since I put on about 15,000 miles a year.

SO, I live in Ohio and want to lengthen the comfortable riding season by bumping up the alternator output (more heated gear please, especially for the woman on back).  There are several options/questions/things I don't know.  I have found on the forum that stock output is 374 watt, at 5000rpm.  I max this out with a heated jacket and PIAA lights (even with LED replacements on instrument lights, signals and brake light).  Yes, I do ride with both the jacket and lights on high at night.

?Did Honda make other engines with similar stator but with a larger output (for an easy swap?)

?Has anyone tried an aftermarket stator, for example those available from Rick's Powersports, or Esport?

Street Motorcycle: HONDA VF750C Magna, 94-03
Replaces OE Number(s):
31120-MZ5-004
Street Motorcycle: HONDA VFR750, 94-97
Replaces OE Number(s):
31120-MZ7-004
Street Motorcycle: HONDA CBR1100XX Blackbird, 97-98
Replaces OE Number(s):
31120-MAT-004, 31120-MAT-E01
Street Motorcycle: HONDA CBR1100XX Blackbird, 99-03
Replaces OE Number(s):
31120-MAT-E01, 31120-MAT-004



It looks like these bikes all share the same physical size stator, maybe you can look into how these bikes and their charging systems output?

[hop along]

It's seeming like all the online sources popping up are using two similar part numbers for stators: ESG520 or 21-130.  Even the RegulatorRectifier.com site.  hopefully I hear back from the two sites on actual outputs early this week.
I'll start digging into outputs on the Blackbird and VFR 750 to see what I can find and see if there is a comparison.  The only place I've seen this info on the Magna was from this forum, so I'm not too sure where to get that info.....

I haven't had battery issues (and ride the CRF in the winter, not the Magna-too much salt and grit on the roads here for my tastes) in cold weather.   I also don't think I see the heat many listers here see.  Though there was last July when I rode near Houston in 110 degree heat-but at that point I was worried about ME roasting, not the bike.  I don't know how y'all ride in that!

Meanwhile, playing on the ol dirt bike in Ohio (where it's 45 degrees and raining in january-what the?!?!?)
Hop Along

[drkngas]

Hey Hoot, I purchased that LED battery gauge in chrome on Amazon for $30. Looks ok right below the gauges.  Works great in letting me know it's time to tricklecharge.