Headlight issue

[Pgosling]

Hi All

My headlight stopped working on main beam - I could flip the switch on the left hand side and get the FULL beam.  I took the bulb out and it was blown!
I replaced it with a new bulb and I still have the same issue?

Any ideas?

Many thanks

[CROSSBOLT]

There is for most of us HIGH beam and LOW beam. The problem sounds like headlamp bulbs blow out which indicates high voltage which means you have no regulation. This sound correct?

Karl

[Pgosling]

Hi Crossbolt

Yes this sounds correct. 

[CROSSBOLT]

Do you have a multi-meter and basic metric tools? Do you want to troubleshoot this yourself?

Karl

[Pgosling]

Hi Karl

Yes - have basic tools and multimeter - if you could may be point in the right direction that would be great?!

[CROSSBOLT]

Awright! First, you will have to uncover the rectifier---regulator by removing plastic at the front and below the headlight. This will be the most difficult and time consuming part of this project! Plastic removal should be done at 70 F or warmer so the locking tabs are not broken. In the mean time I will try to post the test procedure.

Karl

[CROSSBOLT]

Once you expose the reg-rect here are the test points on the little block with fins:

                              RED   YEL

                              WHT  GRN        This is end view, WHT & GRN are on the mounting side.

This is what you should see on your meter:

Probe +      WHT      YEL      RED      GRN
- WHT             -           inf      3-50k      inf
  YEL            inf             -         inf        5-100k
  RED           inf           inf          -           inf
  GRN           inf         5-100k     inf          -     

The service manual is really fussy about the brands of multimeters to use for this test for some reason and is very persistent about what RANGE you should be on for each test. They are NOT real fussy about the readings in different manuals for different models USING THE SAME PART! So take the values with a grain of salt. Count on this: there are NO zero readings and "inf" means infinity and nothing else will do! Let us know what you find.

Karl

[Pgosling]

Thanks for the info Karl

I ended up having to get the bike into the garage anyway as it was bogging down badly and really struggling on hills.

It turned out that it was overcharging so was blowing the bulbs - also had to have new battery, variator, carb and rollers!!

Running like a dream now!

Thanks for you assistance anyway!!  Appreciated!

[CROSSBOLT]

You left out the part about what was done that made all these problems go away. Please tell what the shop did.

Karl

[Pgosling]

The battery had always been flat - so electric start wouldn't work, I never had a problem until the headlight bulb went, I just always used to kick start the bike. 

They reckon that the battery was now so bad that it was overcharging and this was causing the bulb to blow straight away.

So they replaced the battery which solved the overcharging issue. 

The carb was in need of a clean and tune up - but because the cost of a new carb and fitting is more or less the same as cleaning and tuning the old one they replaced it.  The removed the restrictor and changed the rollers and variator and this means the top speed is now approaching 50mph and the bogging down issue has been resolved.

[CROSSBOLT]

OK, that's the way! Thanks!

Karl