race loom alternator, only 2 yellow wires?

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banner001
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race loom alternator, only 2 yellow wires?

Post by banner001 »

hi there, almost sorted my race loom - im wiring the ignition "on" when my resistor arrives, and ive decided to junk the rest of the junction box (ive already removed the wiring to the fuses in there).

i also need to buy a soldering iron, all in good time :D

ive also wired up my stick coils - the cbr600 '07 coild are the correct length, lets hope they fire fine, if not the old coils are going on (but they weigh 360g more...) and ive bought spade connectors so i can swap easily between the two.

but my question is this, whilst looking through the race-loom diagram i see that only 2 of the yellow wires from the alternator go into the reg/rec...why is this? if it because the load over the battery is now less? or is it that the kit alternator only has 2 wires from it?

and which of the 3 yellow wires do you remove, i know where it is on the diagram, but where does that equate to on the actual alternator?

cheers guys!
UK ZXR400 L3 (1993) - Fully restored and on the roads, my green beast!
JPN ZXR250 A2 (1990) - Revs to 19,200rpm... 'nuff said :smt003
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mick41zxr
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Re: race loom alternator, only 2 yellow wires?

Post by mick41zxr »

Yep,
Done so alt only runs as single phase. Supplies enough juice for racing.
If you want a zxr250 alt & flywheel bolts strait in for slightly less weight & centrifugal forces to spin up.
M
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banner001
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Re: race loom alternator, only 2 yellow wires?

Post by banner001 »

cheers!

so you can cut ANY one of the three alternator wires, or is it a specific one? i guess not, but id rather be 100% :D

just waiting on a few connectors now and my race loom will be finished.

and the zxr250 flywheel and alternator, i guess thats an older one ('88-'99), one of the 19,000rpm red-line originals?

edit: and did i read right that you also need to drop the 30A main fuse down to 10A?
UK ZXR400 L3 (1993) - Fully restored and on the roads, my green beast!
JPN ZXR250 A2 (1990) - Revs to 19,200rpm... 'nuff said :smt003
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mick41zxr
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Re: race loom alternator, only 2 yellow wires?

Post by mick41zxr »

Yep inline 4 250 alt & flywheel drop in. Leave alternator unmolested. Remove pin & wire from loom side. Doesn't matter which one, will drop it down to single phase, chase it back to rec reg.
M
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Re: race loom alternator, only 2 yellow wires?

Post by AFM327 »

mick41zxr wrote:Yep,
Done so alt only runs as single phase. Supplies enough juice for racing.
If you want a zxr250 alt & flywheel bolts strait in for slightly less weight & centrifugal forces to spin up.
M

Mick, any idea on the weight difference? The alt appears in photos to be similar to the 400. I keep thinking I'll buy a true race alt for the 400 someday.
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banner001
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Re: race loom alternator, only 2 yellow wires?

Post by banner001 »

cheers guys, the last of my connectors should be here today or tomorrow along with the shims i need for the valve clearances. should know if the loom is working this weekend (although there are so few wires with the race loom that im fairly confident ive traced them all right and that it should work first time :D), ive retained the spade connectors for the coils, so if the ones ive bought are duds i will know as i can just use the stock coils for the time being...but the sticks do look good...ram air he we come :D
UK ZXR400 L3 (1993) - Fully restored and on the roads, my green beast!
JPN ZXR250 A2 (1990) - Revs to 19,200rpm... 'nuff said :smt003
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mick41zxr
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Re: race loom alternator, only 2 yellow wires?

Post by mick41zxr »

AFM, look same in photo's but smaller in diameter, not sure of the weight difference but 250 ones are about 20mm less in diameter. So moment of inertia difference is substantial.
If you want, the BDK race alternators are the go, have one on my #1 bike. Really notice lack of rotating mass riding.
Stick coils a a good mod. Give a good spark, enough to drive surface dischage plugs as well.
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banner001
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Re: race loom alternator, only 2 yellow wires?

Post by banner001 »

cheers mick, ill keep an eye out. still toying with the idea of total loss, but the associated costs make it expensive (would need a few expensive LiPO battery's), and if i was going total loss i would remove the starter and associated mechanics and get a starter roller and they ain't cheap to buy...and this is only supposed to be a bike for a bit of fun now and then, if i can get a cheap decent engine i might look at modifying it in a bit more detail, but for the time being im keeping the engine stock for longevity.

and the 30A main fuse, did you drop that to 10A like in the race manual?

thanks!
UK ZXR400 L3 (1993) - Fully restored and on the roads, my green beast!
JPN ZXR250 A2 (1990) - Revs to 19,200rpm... 'nuff said :smt003
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Re: race loom alternator, only 2 yellow wires?

Post by mick41zxr »

Yep as no headlights etc,
Starter motor off relay outside of main loom.
Total loss should be ok, hard wire in a quick connect plug, then cable tie in convenient location so when you come in from a session plug into charger without removing bodywork.
Should get about hr of running off a 7ah batter including starter motor. Start & warm the bike up on battery charger.
Regards,
M
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