HS2 questions

Guys, I have one of those questions that will probably end up embarrassing me to no end, but here goes. I’m cleaning up a pair of HS2s prior to rebuild for the Bugeyes 1275 and I’ve rebuilt 6-8 sets of them along with 3-4 sets of HS4s and HS6s. All of them have ended up being good running easy to tune carbs, so I must have been very lucky in my efforts. The throttle discs on this set are the solid variety vs the poppet style and while they have a few scratches on the flat sides they fit the carb throats well. The question I have is that these throttle discs have a little bump out on one side where it fits in the shaft and I’ve never noticed it before. Is this to help with orientation of the disc in the carb above and beyond having the beveled edge fit the carb throat correctly? If so, what’s that orientation?
Thanks, Rut

Not embarrasing at all - off the top of my head the bump goes up and on the high side of the shaft. I presume to keep them from sliding too far.

JP,
Thanks for the response and the ‘bump’ side is mounted inline with the throttle shaft, but I don’t know if left or right. I can’t ever remembering seeing this before, it’s almost as if these discs are handed.
Thanks, Rut

Rut said:

JP,
Thanks for the response and the ‘bump’ side is mounted inline with the throttle shaft, but I don’t know if left or right. I can’t ever remembering seeing this before, it’s almost as if these discs are handed.
Thanks, Rut

Click to expand...

I wonder if they have slightly less than 90 deg edges - when I say high side I mean the part that hinges up when you open the throttle.

JP,
I hope a picture of the discs will help explain it better.
Rut

All I see is normal wear, Rut. I assume they need throttle shafts at the least.

Kurt.

Kurt,
Enlarge the picture and look at the sides facing each other and you’ll see the tab or bump on the discs. I do need jets and shafts and possibly some viton tipped metering valves for the float bowls...the ABC needles and discs look good (except for the questionable bump), but I’ll need new disc screws (heads are much larger than the originals).
Thanks, Rut

Rut, I see a bump right where the throttle shaft fits which would be caused by wear of the throttle plate moving back and forth. Is that what I should be looking at??

Kurt.

Kurt,
Yes, that’s the spot...so that’s just wear? I’ll order a couple of master rebuild kits and get the show on the road.
Thanks, Rut

Yeah, I think they are pretty worn....the question is, though, will new replacements be better!? I think I would fit them temporarily and see if you think the clearance is really going to be an issue. Just my 0.02!

Kurt.