Brake lining light and carb synchronizing.

[lassenc]

Hi!

The "Brake lining" light on my "B" dash has started to come on more often, and now it is on all the time. When this light is on, the brakelight is also activated.

What does it do? Where is the contact?

Also.

My left cylinder is pulling the load. Is there an article on synchronizing XS650 carburettors?
Where do I find the connectors for the instrument? And where do I find the adjusting screws?

My carburettors are the ones with an aluminium top lid and a flat choke activator.

 

[5twins]

I'm pretty sure your model has an electric brake wear sensor switch on the rear brake plate. It's supposed to turn that light on when your brake shoes get worn out so maybe they're reached that point. It could also be that you just need to readjust the brake light switch.

I don't think your carb set has any place to connect sync gauges. Sync them by ensuring both throttle cables have the same amount of freeplay. Mix screw settings are given in the carb guide.

 

[lassenc]

I only have one throttle cable!

 

[littlebill31]

I would go to the tech section. The first carb thread has the carb guide, which would be the first link. It's a must to read. It is mostly for the BS38 and 34's, but it helps. There's are other links as well.
The brake wear switch is next to the operating arm on the rear drum.

 

[littlebill31]

Go to mikesxs or the carb guide and I'd what type carbs you have.

 

[lassenc]

I would go to the tech section. The first carb thread has the carb guide, which would be the first link. It's a must to read. It is mostly for the BS38 and 34's, but it helps. There's are other links as well.
The brake wear switch is next to the operating arm on the rear drum.

I looked for that switch as I thought there to be one as well, however, I can't find any wiring to the rearwheel. Have to check again I guess.

 

[littlebill31]

The rear brake light switch is behind the pedal, mounted to the frame. The "wear" switch should be on the drum. You have to adjust the brake light switch sometimes. There is a spring connecting to the pedal which pulls a little plunger out of the switch. 2 nuts allow you to turn the threaded switch body closer or farther to adjust length of the spring to pedal. That caused my brake light to flicker sometimes.

 

[5twins]

If you have only one throttle cable then your carbs are not original for the B model. You have a later set, anywhere from '77-'79. You'll need to I.D. them to determine proper jetting and mix screw settings.

This later set should have vacuum take-off ports just below the mix screws. They should be blocked with a flat head screw. You can mount nipples in them to attach the hoses from a sync gauge set .....

Syncing is done by adjusting the screw in between the carbs on the linkage. It controls the speed of the right carb. Match it to the left one. The idle adjustment screw on the left carb adjusts the speed of both carbs together .....

 

[littlebill31]

What year bike? You say you have a "B"? I didn't think they had a "wear" indicator light.

 

[lassenc]

I don't have a "B", but my dash is a "B".

Where do you guys source the nipples?

 

[5twins]

We're not mind readers here, lol. In order to help, you need to tell us the year of your bike. They only made these things for like 14 years, lol. Most of what I wrote above probably doesn't apply and was a waste of my time. Good luck fixing it.

 

[lassenc]

I don't know the "year" it is a mix-match, that is why I wrote ""B" dash"

 

[lassenc]

And it wasn't a waste, I have those carbs right there.

 

[XSLeo]

Look on your title. It will tell you the year of your bike. If your bike has a B dash, it maybe a 74 or 75. On your rear brake plate there is a switch mounted by the shaft where the arm goes on. The switch is activated by a detent on the shaft. If the shaft turns far enough to make the light come on the brake shoes are worn enough to need replacing the shoes.
Crossreferencing the frame number on one of many year/model lists will identify the year. The engine number by the front engine mount will tell you the year of the engine using the same list.
When you find all this out you can put it in your signature so it will be on every post you make and can help you as well as us to help you.
Look at how others have this listed.

 

[lassenc]

No one has been able to id it yet. My frame number doesn't match any of the intervals. 447-6xxxxx as I recall. The title says 1977. The exhausts and carburettors are definitely not from a "B". The forks are 34mm.

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[weekendrider]

The nipples can be sourced at 650 Central. Look at your wiring in the bucket something is feeding the light, dash and brake. This may be a faulty earth or hot wire rubbed through?

 

[XSLeo]

On the model list I use the 447-600101 is the first number for a 77 D. So you bike is a 77D. The 77 D was the first year of the 35 mm forks with the single piston brake caliper. If your forks are 34 mm does the caliper mount on the front or rear of the forks? They mounted on the front on the 75 B and older bikes. On the 76 they moved the caliper to the rear of the fork. I think that they used a different damper rod inside the fork. A one year item.
It does sound like a bike built from several years.
I've seen the balancer nipples on Ebay.