Alternator charge failure

[vigo]

Engine running and ameter shows slight discharge, presumably ign running on battery. This was when riding, the ameter flicked to high charge then fell to slight discharge. Headlamp on, revving engine, no change to high discharge indication.
Have checked for continuity to earth on the wipac alt wires, white, orange and green, no short to earth. Bullet connections good.
This was a sudden occurrence so I don't suspect rotor magnetism.
The manual details the alt and reg/rec test procedure which leans me towards a challenging know how direction and equipment deficiency certainly where the bike is currently located.
Perhaps it's time to replace the rather ancient looking reg/rec with a solid state from club spares.
Do any of you more electric savvy gents have some test tips or advice, appreciated.

[vigo]

Thought I'd see if there was anything obviously wrong with the rectifier. This I read in the manual was factory set with with a nut not to be removed then attached to the toolbox. Well, it was attached to the rear mudguard such that a bolt was passed through from the rear THEN rectifier fitted with 2x nuts in a locknut principle. This probably during earlier refurb. Anyway, it had worked up until now but I think a replacement is due.

[dave16mct]

If you're changing your old rectifier for a reg/rec why not change to 12 volts. It's a much simpler system. There's lots of info on it in the tech section.
Dave.

[vigo]

That's a sensible suggestion Dave except the battery and coil are new. I was thinking to replace one for one, the thing that looks like 2 beer mats stuck together. Seems the club spares has them for about £6. Otherwise with bulbs etc I'd be into about £75, is that a fair estimate?

[dave16mct]

Yes if you're happy with the 6V system that 's fine. At £6 it'll be a solid state rectifier, a straight replacement for the old one. Dave.

[vigo]

Well, the cause of the charge loss became immediately apparent. After getting this G5 on the bench, I fitted a solid state rectifier and stripped down and removed the gearbox (not for the first time). I'm determined to fix that infamous gearbox leak (mainshft bushes are shot).
Anyway, removal of the drive side casing exposed the alternator rotor had left its location with the nut and plain washer jammed in the stator. I see the club has a tab washer as replacement, we can see why. I'll make one.

Question gents, one of the stator coils has been shaved slightly, no wires broken and no short to earth. I figure the worst could only be a slight drop in output of said coil if the wires contact each other. Is this a fair assumption?

[dave16mct]

Give it a try, see if it works OK. Fitting LED bulbs would help it out.
Dave.

[vigo]

Alternator rotor refitted with tab washer and casing and stator temporarily fitted without oil. Current test iaw workshop manual ie multitester in series with negative from battery agrees with the bikes ameter and shows battery discharge to ign with engine running in all switch modes.
The next will be an ac test with a 1ohm resistor directly from the stator bypassing the newly installed solid state rectifier. I fear this could be going in a forced 12volt conversion direction with replacement alternator and asociated bits.£££.

This entry is originally alternator charge failure but in the meantime my efforts to stop the gearbox leak have failed with the realisation that unless the main RNU205 were a sealed bearing, which of course it's not, oil will always escape passed the rollers. Despite the generosity of Paul B (fixit) who lives near me in Chester and gave me some spares left after selling his G5, including a sleeve gear with decent bushes, the leak is still there. Thanks Paul.

[vigo]

Well ,I checked the ac output from alternator iaw the manual. 1ohm resistor in parallel with voltmeter, although difficult to guage engine rpm I never saw more than 2volts from either set of stator coils. The conclusion can therefore be made iaw the manual that the rotor magnetism is low, although it will keenly grab anything ferrous nearby.
Any tips gents on the way forward?

[vigo]

I decided to remove the stator completely to the workbench. I found 2 wires disconnected which put part of the 2x3 coils out of circuit, it's a wonder I had any volts at all. These where resoldered and the 2 coils with copper wire scuff damage due to the rotor nut undoing were insulated with the kraken tape Paul B details in the club forum, thanks Paul. Everything refitted and engine ran with 6 volts on orange but I saw 7volts on green wire. The 6 volts would account for the coil scuffing perhaps. Connected up to rectifier, ran engine and bingo ameter charge indication.
I then switched the headlight on and saw a discharge but wasn't revving much, I think a good run out is needed when weather warms.
Thanks again to Paul and all the other forum discussions I found.