1975 Sportster 1000


I think it's kinda a fuel issue... It has a Keihin carb(butterfly type) But had 180 and 72 jets( accelerator pump was an 80)

I think that is WAY too big, leading me to think this carb was off a Big Twin... I had another trashed Keihin laying around... it had 160 and 68... i pulled those, cleaned them...

still getting a top end cut out...

What size jets should it have? I know Big twins ran like a 165 main... I think

 

Ok 160 & 68 is lean at idle... I guess .040 over and open pipes needs more fuel

 

Its been a long time since I was into the carb on my '83, but I think the stock jets were a 160 and a 52. With a more open exhaust and air filter, I'm running a 165 and a 55 (to the best of my memory). If the idle mixture screw is still sealed from the factory, remove the plug and adjust it - the factory setting is really lean. I'd guess the stock carbs for the '83 and '84 models were pretty much the same.

 

Well when I installed the 160/68 combo it was pretty bad... lots of de-acceleration pop... not the sexy kind either... surging at lower throttle... it was without a doubt lean as ****