felt washer size.

[Tbell]

This is part of another post but need more info. Does anyone know the exact measurements for the felt carb washers? Cant find anywhere. Thickness, OD and ID. I know I can measure the old ones but they have been compressed for 32 years. Thanks in advance. Tom

[octane]

Now this is a bit useless:
I just realized that you don't have a problem
with the throttle shaft felt washers
but you leak is around the choke shaft

Well, well I just got out a set of NOS parts for
early carbs that came as part of another purchase
of carb parts.
The parts came as a 'link-set'.
In the package there was 2 band new felt-"washers".
They do not have a number in the part catalogue,
but only came with a complete 'link set'.
Anyway; I measured them, so you bloody well have to watch this:

.-)

ha ha ha












Maybe someone can find use in those measurements.
Just a warning in case someone wants to replace theirs:
they sit behind a brass-washer that is part of the carb-body




so to replace them you have to remove the shaft
and to do that you have to remove the 'butterfly'
that has some very special screws:

Throttle open. Showing the 'rear' of the screws:



It's impossible to see from the photo but;
from new the last bit of the screw is hollow and has a very small slit,
that has been punched 'open' ,and broken of
to create an outwards tension. in the remaining part of the screw.
This will see to it that it can not move out again.
You really don't want those screws sucked into the cylinder.
Of cause they are not meant to be reused.

Also putting back the butterfly in the right position
so it doesn't rub against the body is not for everyone to do.



Now your problem is with the choke-shaft:

Bad news:
there is no washer....no nothing.
Just runs in a hole that fits the shaft....in your case: not.
No space or provision for a felt-washer.
I didn't know, but just took a tired old carb apart:



Nada!..strange but true.
The choke shaft/butterfly is not shown in the parts diagrams.
Only there as an integral part of the carb. body.




PS:
no I don't have a life.

[Tbell]

Octane: You usually come through, I'm going to start calling you Superman. My leak is at the throttle shaft. This is exactly what I need. Someone else has a leak at the choke shaft. Mucho thanks! tom

[octane]

... My leak is at the throttle shaft. This is exactly what I need.

Ahhh! Great!

Someone else has a leak at the choke shaft. Mucho thanks! tom

You're welcome.

Now when you do replace them:
please come back and let me explain how to
re-assemble the shaft/butterfly.

(in case you don't know, that is)

.-)

You're gonna need the strongest
Loctite thread-lock (or similar product) you can find.
They do come in 'grades'.

.

[Tbell]

One other thing. Is the felt washer installed dry or does it need to be saturated with some type of lubricant? Tom

[Tbell]

Might as well start now with the explanation. I'm going to try it. Can't do any damage. Either way, if I fail, I will have to buy another carb body. Later! Tom

[octane]

One other thing. Is the felt washer installed dry or does it need to be saturated with some type of lubricant? Tom

I would ,and have done on mine, lubed them with thick oil,
like transmission oil W90.

On complete carbs it can carefully injected
with a syringe/needle.

Call me anal....you wont be the first one to that....ho ho.


I'll go looking for a life.

[Briang]

I can see how a throttle shaft leak would need a seal because it is after the needle sliders and the venturi action of the carb body and a leak in that area would have performance consequences but, isn't a choke shaft leak coming from the side of the air intake, before any carburation action? Any slight air intrusion there would be just included in the atmospheric air being drawn in to the throttle body, IMHO. I would think the only real consequence would be that this air would not have first passed through the air filter.

[octane]

I can see how a throttle shaft leak would need a seal because it is after the needle sliders and the venturi action of the carb body and a leak in that area would have performance consequences but, isn't a choke shaft leak coming from the side of the air intake, before any carburation action? Any slight air intrusion there would be just included in the atmospheric air being drawn in to the throttle body...

Good thinking.


Darn!!!...why didn't I think of that!


.-)

.


.

[Briang]

It was your pictures, Octane, that pointed that out. The choke is not something that normally would not need replacing given that in the lifetime of a motorcycle it would move, what, a couple of thousand times at best? That is why they made it with those one-time fasteners.

The throttle, on the other hand, moves millions of times, possibly, in the life of a bike.

[octane]

It was your pictures, Octane, that pointed that out. The choke is not something that normally would not need replacing given that in the lifetime of a motorcycle it would move, what, a couple of thousand times at best? That is why they made it with those one-time fasteners.

The throttle, on the other hand, moves millions of times, possibly, in the life of a bike.

Your're right!...makes sense.


BTW: the throttle butterfly IS attached with those
screws (and the choke butterfly as well)

[mooseheadm5]

Those screws are peened in place to prevent them and the butterfly going through the engine.

[Tbell]

I have the carbs apart to replace the felt washers and I noticed a small hole in the carb body behind the hole that the throttle shaft fits through. I am wondering what this is for. It exits where the felt washer is seated. Maybe lubrication of the washer with gasoline???

[octane]

No...oil!

Gasoline does not lubricate
and anyway it evaporates in a minute.

[octane]

Those screws are peened....

Ahh; that's the word...thanks.

Looking closer it does look as if there's
trace of solder?!..as well.