Knecht air cleaner question

[John Wurner]

Two Knecht air cleaners I have will only slide on to the Zenith carbs about 1/2".
There is a band welded inside the opening (great welding job incidentally) 1/2" from the bottom that keeps the carbs from going any further.
This reduces the openings from approx 70mm to 66mm.
Any reason for this that you can think of?
I cant take the welded pieces our without ruining the air cleaners.
John

[Alan Hall]

I think that piece is there to prevent the air cleaner from riding down and sitting on the carb top where it could wear a groove in the carb top. I believe later air cleaners had this feature, yours might be original or somebody's attempt to duplicate the feature. I think the factory version might have had a small o-ring that sat between the band and the carb entrance.

[John Wurner]

Thank you, Alan.
I have not seen that before but it might make sense.
I will try to tighten the clamp and see if that works.
John

[Tom Keating]

Inside where the neck gets smaller, there is a rubber O ring. It is for allowing the air cleaner to sit on top of the air horn of the carb. Look real close for it.

[John Wurner]

Here is a picture

[Vic Skirmants]

Those started with the C models.

[John Wurner]

Thanks, Vic.
I assume by that its a factory change.
John

[Jim Breazeale]

Thanks, Vic.
I assume by that its a factory change.
John

Yes, it was.

[Brad Ripley]

Anyone could figure out the dimensions of that O-ring? or can measure the diameter inside where that O-ring goes?