no neutral light

[derek1922]

Hi guys.
Thanks for all your help over the past few months with the restoration,you've all been a big help.
The bike is almost done,I still need to decide on a colour to paint the tank and side panels but that can wait.
The last (I hope) problem is I have no neutral light,it starts if i pull the clutch in,bike runs really well up to about 3.5k revs and starts spluttering but past that and it runs well again,I found a split diaphram in the left carb and a shot float needle in the right carb.
The light was working when i got the bike but it has decided to take the huff and stop working,to be honest i connected the THIN positive cable to the ground post on the battery a few months back and realised my error within a few minutes (probably because that bike wouldn't start) and i wonder if the two are connected.
I don't know if having a neutral light is a requirement for passing the MOT (inspection).
Any thoughts would be welcome.
Could i have shorted the starter relay somewhat when i connected the cable wrongly ?
BTW, I'm thinking of painting the tank etc army green or maybe a sand colour,any comments,photos welcome because what i imagine it would look like may not look nice in reality.
ALBA GU BRATH ( Scotland forever)

[montmil]

Check the two wire connections at the neutral light switch for security and clean contacts. Do a continuity check on the switch using a VOM. Then start a wiring trace. The electrical component of these switches rarely fail. It's the poor OEM design that often leads to a 'incontinence' problem... drip, drip, drip.

[derek1922]

Is the neutral switch at the bottom of the gearbox?
Thanks for replying so quickly.

[Kurt in S.A.]

What bike are you talking about? The neutral switch came in two varieties...an "innie" and and "outie". The "innie" was used up to about 1975 and has only one wire going to it. It gets pushed in to make ground, which should turn on the neutral light. After that, the "outie" gets pushed out to make contact and should have two wires to it. This switch doesn't actually make the ground, it just connects the two wires, one of which ends somewhere attached to the frame.

To confirm that the light is working, that the wire (not the ground one) and use a paper clip to connect to the frame. If the light comes on, then the problem is the switch.

Kurt in S.A.

[derek1922]

Thanks,the bike is a 1983 r65,sorry I should have been clearer.

[Jean]

kurt, My 78 R100s has a neutral switch with only ONE wire.
Did they have 2 different neutral switches as late as that?
PS to derek. The neutral switch IS under the transmission. It's right difficult to get at. BUT possible!!

[robert]

4 spd gearboxes had 1 wire, all 5spds had 2.

[Kurt in S.A.]

kurt, My 78 R100s has a neutral switch with only ONE wire.
Did they have 2 different neutral switches as late as that?

As mentioned, you really should have the two-wire switch. My '78 /7 does. The only way a one-wire switch would work is if the internal mechanism was changed out. That changed where the recessess or humps were on the actuation plates.

Tom Cutter stated that the one-wire switch was typical for the 4-speeds and the early 5-speeds. The two-wire came to use after that point, maybe midway during the '74 models or maybe beginning with the '75 models. Any chance your transmission is really an early 5-speed?

Kurt in S.A.

[derek1922]

It's a two wire switch,I'll try the paperclip thing tomorrow.

[derek1922]

Tried the paperclip,no go,still no neutral light.
Took the tach of and opened it up,water/moisture has gotten into it at one point,corrosion inside,cleaned up everything,some of the bulbs useless but the ones that were working i used one for the neutral light oriffice,still nothing,too cold to ccccarry on tonight so tomorrow I'm going to run a wire straight from the brown/black wire from the multiplug at the back of the tach to an earthing point to see if it's the tach that's at fault or not.
suggestions welcome as usual.