Sparx alternator

[grizld1]

Hi Dave, you're correct re. the fuse. Re. clearance, if you're not getting a "no-pass" at .009" I don't think you need to worry that the snug fit at .008" is too tight; the flat gauge is having to conform to a curved surface, so the fit probably feels tighter than the actual gap. If there's a lot of difference as you check clearance at the same point on the stator at different crank positions, you might want to pull the rotor and set up a dial indicator on the crank to inspect runout and find out whether the variation is coming from there (a potential problem if it's excessive) or from the rotor itself. But it sounds as though the variation you're getting is less than .001" if I'm reading you right, and that shouldn't be cause for any concern at all.

[islanddave]

Ok thanks Griz. That is what I thought about the air gap. I was just a little cautious because I screwed up my rotor and stator before when the rotor came into contact with the stator. (this was my fault!) and I did not want a repeat performance of this again! Yes you are reading me right about the .008" and .009" clearance. I can get both these feeler gauges in at the 12 o'clock position. I just wondered if I needed exactly .008" al the way around. Just over thinking again!! ;D

Thanks for the help, I hope I am done worrying about charging systems!

Dave

[islanddave]

Well I hooked up my Sparx and I am still not charging. I am almost sure that the battery is at fault because of what has been said about how important the initial charging procedures for the batteries are for the Sparx system to work. I can get about 13.8 volts across the battery terminals if I rev the snot out of the bike, but at idle the volts just keep dropping.

air gap set
black to battery ground
red to battery positive through a 20 amp fuse (fuse good)
three wires from reg/rec to the stator assembly

Maybe I will just buy another battery. I am running a boyer, led taillight, headlight, no signals, and kick only. I am using the three phase Sparx......what is the smallest battery that I could use?

Thanks Dave

[grizld1]

I'm no expert on electrics, Dave, and I hope wiser heads will jump in and correct me if I'm wrong; but given the vulnerability of PM system reg/rec units to failure due to overheating the built-in heat sink, I suspect it would be best to use the OEM battery.

[islanddave]

Anyone?

[islanddave]

Anyone?

[skidro]

Check out this link. www.thechopperunderground.com/forum/index.php?showtopic=36508

[grizld1]

Thanks ski, that's great information; but here's the issue. With the OEM alternator the reg/rec kicks out power to the alternator field coil so the alternator stops charging, then kicks it in again when voltage drops. With a permanent magnet system this doesn't happen; the alternator charges all the time, and the reg/rec controls battery voltage by dumping excess current to a heat sink. Under certain conditions this can be a problem; for example in prolonged high speed running, the reg/rec can overheat and fry components, usually rectifier diodes, unless there's enough load on the electrics to help out. The first you know of it is when the battery starts to boil because it's being hit with some unrectified AC. My worry would be that the small battery may cause too much load on the reg/rec; maybe a valid concern, maybe not.

[swinewerx]

You know, at first with my first xs 650 I did the kick only along with tail/brake and head light and used a very small battery that seemed to be twelve volts, it's appearance looked that way. After about a few batteries I finally discovered my regulator was very bad causing my system to over and under charge making any battery there puke a lot, I was still learning about this chop so I knew it would eventually be figured out. And it did, I just don't like the charging system when it requires a set of brushes and all so delicate. I am very used to hondas, this is my fav chop and it does great, if I teach myslf to tig weld and weld aluminum it is on then to a permo magnet charger

[Burns]

Though I do not hold myself out as an expert in the area, if PM charging systems needed big batteries I don't imagine Sparx would be selling their single phase systems at all.

PM systems need a regulator/rectifer with sufficient mass for the heat sink required and mounted where it gets enough air-flow to dissipate the heat generated from the excess current.

I'm sure Sparx knows how much mass is needed for its RR, so mount that RR where it gets enough breeze.

With a capacitor you don't need any battery at all.

I'm running a junk yard hybred, using MrRiggs bracket, and have the RR in the breeze mounted to the lower triple clamp (where god and BSA said they were supposed to go).

Not enough miles on this set up to qualify for expert testimony, but, so far, so good with 13.5 v pretty much anywhere from idle to redline.

[primus]

was wondering if could someone post the outside diameter of the sparx rotor ,thanks