New Amals, slide sticks

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"Sons of Arthritus"
Jan 14, 2004
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I just boiled out a pair of new Amals that were lacquered up from non use. When I reinstalled, the left slide stuck. Needless to say I was a little p#&%.
Breath in, breath out. Breath in, breath out. That's better.
I started to remove the left carb. When I loosened the inner manifold screw, the slide snapped shut. Everythings fine. Tighten it up, slide sticks.
Whats going on?? Alignment issues, that's what. The inner bosses where the idle screw would be but are blank, are interfering with each other. When the carb was tightened. it was distorting the body, thus making the slide stick.

Comparing these carbs to other carbs from Nortons, there is a difference. This inner idle boss is machined for clearance on the three 932's on my bench. These all came off of Nortons.

I noticed a set of NOS carbs on e-bay. These idle bosses are also not machined. So beware, new carbs or any parts for that matter can have issues too.
slides binding


It's hard to believe Amal 932s would touch at this point. I just checked mine and I can get a finger between these bosses. If the surface that mates to the manifold is not flat the slide will bind when the socket screws are tightened. It makes sence when they are loosed the slides would free up.
Thanks Dave, I planned on filing them. What surprised me is it hadn't already been done. This is my first experience with new replacement carbs. I would expect anyone who has done before would know about this. This bike has supposedly been gone through by a shop to the tune of $2200.00. New carbs were part of it.
Goes to show you, there are Brit bike shops, and then there are 'Norton' shops.

David, you are looking in the wrong spot. I just measured the clearance of a pair of 930's on a 71, measures .035. Check out the angle of the idle screw boss. The ends need to be file in a vertical plane. Stock carbs have this done.
Carbs filed, reinstalled. Everything is fine. Breathing has commenced.
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