Thanks for the advice Dave ☺
I had a feeling the needle spacer could come down a little bit more. I had moved it to the lowest notch on the needle and was hoping to get away with that. Still has a little surging at 1/8 to 1/4 throttle but I've been trying to ignore it. Probably need to reduce the spacer a little as well (I'm having trouble finding washers in the local shops that)
I put the 55 pilot in last night and took it for a good run to warm up the bike and test it, just to see what effect it had. I wouldn't say it ran any better, however it did virtually eliminate the afterfiring (that was nice, but not critical for me). I'm probably at the stage of fine-tuning now.
With the 55 pilot jet the fuel mix screw gives max rpm at about 3/4 turn CCW out from fully in. At fully in, the idle slows just a little. At 3 turns CCW the bike almost stops.
Whereas, with the 52.5 pilot jet (stock), max rpm is at 1 1/2 turns CCW. The bike almost stops at fully in. And slows down considerably toward 3 turns out.
That seems to me to say the 52.5 is the right pilot jet.
Looks like I'll be reducing the spacer a little.
And I have a 152.5 main jet on order.
Dave wrote on 01/09/17 at 17:55:46:It has been my experience that the needle position is far more responsible for the 1/8th and up throttle setting than the Pilot jet. If you feel a slight surge at low throttle settings, try one less washer on the needle before you go up on the pilot jet. You want a pilot jet that is sized to work best when the screw is set between 1.5 - 2 turns.....if you can turn the fuel screw all the way in and the bike is still running well - the pilot jet is too big (idle speed set about 800 rpm for the idle fuel screw adjustment - then back up to 1,000 - 1,100 when the adjustment is completed).