Everybody polishes the outside of the carbs.
IF you do this, take your time and be patient as you can ruin a set of carbs if not done with care.
The bores of the carbs can be polished also to smooth the air flow through the carbs. Heres what I do:
I made a slightly tapered arbor for my lathe that I mount a peice of 400- 600 grit emory cloth to. This is used to get rid of the casting mark on the engine side of the slide and to smooth up the bore. It is kept out from the slide area by about 2 mm (if you get into the slide area, you may alter the passages in the bottom of the venturi, you dont want to do this).This is the only place where the actual stock dimensions are changed (to get rid of the casting mark). What you are attempting to do is to smooth the bore by polishing it with the emory cloth.
I then use the 600 grit emory cloth to polish up the whole venturi (YOU ARE NOT BORING THE CARB, YOU ARE JUST POLISHING THE VENTURI)You dont want to sand the heck out of the bore you just want to lightly sand it to smooth the bore.
I lightly (LIGHTLY) sand the bore where the slide is to polish that part also. I use 0000 steel wool on the slide. The slide moves much easier in the bore when it is polished this way.
I usually finish it up with a polishing with Never Dull (polishing wadding)
Of course, you will need to clean the heck out of the carb when you are done. I usually clean them before and then reclean them after.
The picture shows the arbor, The single carb has had the bore polished and the casting mark removed, and the other set shows the carbs as they left the factory. I took other pictures of the bores, but my camera isnt that great.
Fish
Post edited by: The Fish, at: 2006/05/04 09:38