Sleeving Vintage Amal carburator
Was wondering if anyone has ever resleeved the slide bore of a carburetor. The Amal concentric carburetors were used on vintage British motorcycles and, in fact, they are still available today. The problem is that they are made from a relatively pot metal (not aluminum). The slides are made from the same soft material. The result is a galling action leading to wear which leads to improper fuel mixtures. I would like to ever so slightly over-size and true-up the carburetor slide bore. The slide would be turned down and a brass sleeve affixed to the slide. My thoughts were that a reamer would do a more exacting job than trying to bore on a lathe. An aluminum cylinder with simple steel cutters set in the cylinder should do the job with perhaps a center shaft protruding into the needle seat hole to ensure alignment. This entire operation could be done by hand and a reamer would provide a cleaner finish. As for turning down the slide, I haven't come up with a more simplified technique Both the bore and slide are round of course. If it were only one bike I might take the plunge and buy a set of the new Premier Amal carbs. They, like my effort have a dissimilar slide but with several vintage bikes the cost begin to become prohibitive. I thought it would be worth the try as i have a couple of worn spare carbs to experiment with. There used to be a few old chaps around that did resleeving but they have taken their secrets with them.
Any ideas and suggestions would be much very appreciated. Thank you
We're all on the same page
Olderdan,
Yup those look like the gaskets that I use although I still prefer to mount the carbs using the original Cleave-Lock nuts with a plain flat washer (not the rubber backed washer) - Not really much different but to each their own I suppose.
Tonyfoale,
Unfortunately, oversize slides are not available. My guess is what size to oversize them. They did chrome slides for a few years to avoid the galling action but found that with time the chrome de-laminated and would be sucked into the engine. Anodized slides are sold as replacements and also used on the new replacement premium carbs (including a removable pilot jet). Amal ad re: 600 series Premiums follows though 900 series also available:
"As a further step in the improvement and development of our carburettors we are now offering special light weight versions of our 600 Series Premier carburettors with the body and float bowl cast in aluminium. The carburettors include all the parts developed by us for the Premier carburettor – hard anodised aluminium throttle valve, ethanol resistant Stay-up float, removable pilot Jet and aluminium needle valve and have been comprehensively tested on the road and have already clocked up several trials successes.Genuine AMAL jets guarantee accuracy and consistency of performance.
The aluminium carburettor offers a weight reduction of around ¾ lb over the traditional zinc alloy type."