So you are having carburettor problems and in trying to find out what that problem is, you have discovered that there is air leaks aroung the throttle shafts.

 

Well, surprise, surprise! Here's where I shock you all that think they shouldn't leak.

 

THEY ARE DESIGNED TO!

 

On the left you see a stripped down carb body

 

What do you see right in the place where the felt seal should be?

 

 

 

 

A HOLE!

 

 

 

And where do you think that hole goes?

 

RIGHT THROUGH INTO THE CARB BORE!

 

Ah, you think. There is a felt seal in there to block it up. Well, apart from the fact that a dry felt seal will still leak air to an extent (it really is just a dust seal to stop grit etc. getting into the throttle shaft bore), on each and every set of carbs I have stripped that still have the Honda installed 'seal', the felt has a gap right where the hole is! And the plastic washer  that goes up against it usually has a burn mark at that point, possibly from a backfire.

 

I have talked with Randakk about this; neither of us knows why this is as it is.

 

I have built up carbs with the with new full felt seals or with proper rubber grease seals in place, with no discernable difference in the running of the engine other than a very slight adjustment of the idle mixture screws.

 

So if you have perceived carbs problems, it is most unlikely to be here that you will find the answer.