Triumph Tigress/Sunbeam

I have sent this to the BSA_N_Triumph_scooters group and thought I would
copy to you as well.

I am in the process of converting the everyday Tigress to 12 volts. The
6 volt battery failed so I had to do something, and as I have an
electric starter available I decided to take the plunge. I have had a
bit of a trawl through Google and also read what Tony Spillane says in
his notes. Some say you need a ballast resistor to protect the coils,
others say their 6 volt coils are fine after years of being fed with 12
volts. So after a bit of thinking and weighing up the risks, I bought
the 12 volt battery and put it in. It's a Motobatt MB5U and it's exactly
the same size as the original 6 volt. Bulbs all changed for 12 volt
versions of course. The horn sounds better now.

I gave it a kick and it started just as it always does, no noticeable
difference in idle or general running. I have had an ammeter fitted for
some time and the charge rate is just the same as with the 6 volt
battery, i.e. about 1 to 2 amps if revved a bit. To check the charge
rate with headlight on I removed the headlight bulb, turned the switch
to "head" and the rate went up about 1 - 2 amps. I was told that the 6
volt alternator would step itself up if asked to deliver 12 volts which
I found hard to believe but seeing is believing.

I looked at the alternator connections and they appear to be all mixed
up with the wires not matching the harness wires at all! As it is AC at
this point it obviously is not too critical but it probably explains why
the emergency starting doesn't work.

I am planning to change the alternator wires to the 2 wire configuration
and to fit a regulator/rectifier. Then I'll hook up the starter - really
looking forward to that. I haven't changed to negative earth yet but
will do so in preparation for electronic ignition.

Ivan

Measurements thanks to chipptiger.

Front wheel
Bearings
Part No: 83590-0010 (this is according to my parts list but I think this is wrong)
My measurement: 35x15x11
What came out: FAG 6202
Replacement Bearing: 6202

Part No: 83490-6063
My measurement: 40x17x12
What came out: Hoffmann 117v3
Replacement Bearing: 6203

Oil seal
Part No: 91376-5533
My measurement: 41x22x7
Correct seal: ?????????????

==========================================
Crankshaft
Bearings
Part No: 83590-0010 (2 needed)
My measurement: 40x17x12
What came out: Hoffmann 117v3, Hoffmann 117v2, SKEFKO 6203
Replacement Bearing: 6203

Part No: 83824-4217 (2 needed)
My measurement: 47.6x19x14.1
What came out: Hoffmann LS8v3, FAG LS8
Replacement Bearing: LJ3

Oil Seals
Part No: 41690-0749 (2 needed)
My measurement: 47.6×28.8×7
Correct seal: ?????????????

Part No: 92076-0527
My measurement: 30.5x17x7
Correct seal: ?????????????
==========================================

Transmission/Chain Case
Bearings
Part No: 94076-7508
My measurement: 52x20x15
What came out: FAG 6304
Replacement Bearing: 6304

Part No: 83590-0010
My measurement: 40x17x12
What came out: Hoffmann 117v3, Hoffmann 117v2, SKEFKO 6203
Replacement Bearing: 6203

Oil Seal
Part No: 91476-7519
My measurement: 38x28x7
Correct seal: ?????????????

=============================================
Primary Drive
Bearing
Part No: 83876-0216
My measurement: 35x10x11
What came out: 6300
Replacement Bearing: 6300

=============================================
Gearbox
Bearing
Part No: 83976-0033 (one side sealed)
My measurement: 52x25x15
What came out: ??
Replacement Bearing: 6205