hi , while your in there replace the oil pump drive gear on the pinion shaft original is only about $33, esp if its done a few klms over the years ,
i use to race in the 883 twin sports /roaring sporties & set the heads up for some race teams as well , seen a lot that needed replacing & seen the mess it makes when its been hard ridden & not replaced also. cheers

dr56, just to jump in on the back of this thread, i should also replace the gearshaft in my 94 sporty rebuild (883>1200 S/E heds) thats the vertical shaft that runs off the pinion gear  under cam 2 yea????? and also the 4 lifters even tho i rebuilt them???? would that take away a bit of chatter in the valve train?? and just a comment on adjustable pushrods there swifty i was told i could use my original pushrods in my rebuild, but only untill i did my own measurements on rod lengths did i find that the original rods were 6mm longer than i needed so wen i pulled the rocker gear down both valves were open, no compression, to get that info from anyware was like setting my hed on fire and putting it out with a baseball bat, so a set of adjustables cured that overnite, happy fuggin daze cheers ratz

hi, the vertical shaft that runs up from the bottom, up to the pinion gear is the oil pump drive gear shaft these are normaly O.K. but inspect it anyways it should still have all the flats at the ends of the teeth + all the teeth should look in good nik on there contact surfaces esp in the direction of rotating load ,
its allways the oil pump pinion gear that wears mostly, when we were desprate ( race bike had to be at the race track ) if they are not to bad you can flip it around & use the other side of its load side the oil pump gear works either way around , but beening a race bike they were often pulled apart , not like a street bike .
i don't know what you mean by rebuilt hyd tappets, pre EV sporties you can replace the tappet wheels to save $ , but the latter wheels are non replaceable items. new ones only originals tappets are cheap at the moment under half the $ they use to be .
the wheels on the later tappets, 1991 up sporties wear into the sides of the hyd tappet body in hard used bikes .
allways check gear lash on all the cam gears & pinion shaft cam drive gear , check dry with no oil on the gears,
some aftermarket cams have a bit of tappet noise to do with fast opening ramp lobes + the oil pump is only low presure type hyds need a good oil presure + un airated oil under the hyd piston , the hyd piston has airated oil under it & depress under load , hyd versus valve spring presure, & thats whats the ticking noise is on some aftermarket cams
cams with radial lobes are kinder to the valve train esp at hi revs . cheers

dr56, i meant rebuild as in pull apart and clean,, i didnt mike them and i gess u wudnt at probable 15 yrs old u wud just get new ones, i have a bit of chatter in the top end which i put down to rod assy, like more moving parts theory, as opposed to overhed cams, my cams are new n4,s, and soon off to the dyno, thanks for yor comments its great to get some advise, this forum is such a great springboard for the ideas factory!! i will source some prices for nu lifters around the gold cst, cheers from that fuckin rat