Don't know what to say but on page 1.15 of the Triumph Bonneville, Bonneville America Service Manual (part number T3850902 issue 1 09.2001) Main Jet 110, pilot 40 etc...
I didn't replace the mains the first time (Vera was running way lean) the stealership did. This manual could very well contain more than one misprint but the mains I replaced when I re-jetted after the stealership did, were 115s or 118s can't recall which but they were not 12Xs. Go figure! Vera runs 122 with 48 pilots right now. These were the kits shipped with the Scepters back in July 26 2003. 4 years (almost) and loads of miles later she is running strong.
An error does exist on the above referenced page. The oil volume in the fork tubes is listed as 484 cc. The correct level is supposed to 548 cc (same manual page 11.11). Looking at the tJP page you'll notice that 865 speedmasters came stock with the larger jet kit.
Larry, you had a pre-fire. I have a pre-fire. I would like to think that Triumph was still trying to figure the jetting out and printed the manuals so early that they printed outdated jet sizes.
Yet, given the stealership re-jetted my lean bike with 115/8s, I'd say she came with the 110 as all the early literature that I can lay my hands on says so.
Matter of fact, I'll bet you a shiny beautiful chromed America front brake reservoir that Triumph installed different jets based on who nows what!
Look at the chain guards. Look at the side cover as the Bonneville suffix was phased out. At the tank console wiring harness. How all that stuff changed. I am thinking that my America was oem 110 40.
Who knows? But obviously this is one bet that no one can win.
I say it was the egg first.
