found a BSA 500 single. Engine #bb34.xxx with a small hc stamped under the number. The cylinder and head is cast iron so it is not a gold star? What is it then. A list of BSA engine and frame numbers list it as a '53 competition or competition plunger (mine doesn't have stock frame) is it possible to know the difference. Any info would be cool.
BSA question
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It's not technically a Goldstar without G.S. in the serial number. Goldstars came in ZB, XB (?) BB, DB and DBD (late version and most well known) prefixes I believe. That being said there are BB32 (350) and BB34 (500) alloy top end versions that are very similar to Goldstars and were referred to as "alloy competition" models, but they are not recognized as Goldstars by the Goldstar police. And they don't bring a fraction of the money without the GS in the serial number. I have a '56 BB34A project, they are neat little bikes. If your cases are BB34AXXX and the top end is iron then it was probably replaced at some point. I am sending you a pm.
-Tombat
-Tombat
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tombat hit the nail on the head.
if the crankcases are stamped BB34 they would definitely have come with the small finned competition alloy barrel & head originally.
the BB32 & BB34 competition alloy motors were either 'clippers' (trials model) or a short run precursor to the DB Goldstars, the only difference being i think a slight variation in the head design.
the B33 cast iron top ends aren't necessarily a bad thing, they can still be made to breathe fire and many GS parts are a straight swap, plus i would think being BB crankcases they may even have some extra webbing and a bigger main bearing then the garden variety B31/B32/B33 models.
open up the timing side cover and check the numbers on your cams, hopefully you've got some GS cams in there!
-Nick
if the crankcases are stamped BB34 they would definitely have come with the small finned competition alloy barrel & head originally.
the BB32 & BB34 competition alloy motors were either 'clippers' (trials model) or a short run precursor to the DB Goldstars, the only difference being i think a slight variation in the head design.
the B33 cast iron top ends aren't necessarily a bad thing, they can still be made to breathe fire and many GS parts are a straight swap, plus i would think being BB crankcases they may even have some extra webbing and a bigger main bearing then the garden variety B31/B32/B33 models.
open up the timing side cover and check the numbers on your cams, hopefully you've got some GS cams in there!
-Nick
thanks fellas! Those damn goldstar police! I don't really care if it's worth less to some anal self proclaimed expert. I simply like it, got it for a song, and I'll probably get it fixed up and blast around once in a while. I don't have plans to race it. Just so I got it straight...the top end on my machine has been replaced with less desirable parts than what was stock?. Also there is no A in the number, just BB34.123 if that matters.
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