Hey guys, a quick run down of what my issue is. I have an 01 883 that I just did the hammer 1250 basic conversion on. I kept stock heads and stock ignition (just retarded it a little). I put in a 45 pilot and 185 main, the bike HATED the 45, wouldn't stay running unless I was at 1/4 throttle and it was puking black smoke, even with the mixture screw at 2 turns out. I put the 42 pilot back in and it ran much better, except it's running lean (plugs are white) and it's popping and back firing on deceleration, even with the mixture screw about 5 turns out. I asked hammer and they had no idea what could be the issue, said they've never seen a bike not like the 45 pilot like mine did. Any one here have some advice of what may be going on? Thanks in advance

 

Hi from the UK and welcome to HDF. We have many members with a lot of Hammer 1250 experience over in the Sportster section, so I recommend you call in there.

 

Turning the air/fuel screw out(counter clockwise) on some carbs leans the mixture,lets more air thru passage,less vacuum pulling fuel from pilot jet.
Turn air screw all way back in (clockwise) then back out
1 1/2 turn. This is standard factory setting on most CV carbs. Try small adjustments from there 1/2 turns.
Make sure clean carb/good gas flow/ filter first.
Check web for info for best main/pilot jet size for bigger bore.

 

There is also 44 pilot jet size that you can go to as well. You are not restricted to just 42 and 45.