Should you do the o-ring mod with a boyensen quick shot?

[Luigic81]

I just bought a '06 YZ450f, and the jetting was all screwed up becuase the previous owner installed the slide plate upside down. I went ahead and did the o-ring mod while I had the carb out, figuring I could always take it off later.

Got that slide plate installed correctly, and took it for a test ride today around the neighborhood, it felt pretty good jetting wise, except there is a little stumble when I whack the throttle open quickly.

The bike is all stock motor and exhuast wise, and it's set up for supermoto (if that matters)

current jetting is:

48 pilot

fuel screw 2 turns out

168 main

stock needle in 4 th position

stock 55 leak jet

o-ring mod

boyesen quick shot

twin air filter with no toil and back fire screen removed

I'm in portland, OR at sea level and it's about 63 degrees right now, bike had very little decel popping, almost none infact (thinking about trying a 45 pilot)

Since I never rode the bike before I did the o-ring mod, I'm not sure if that helped or hurt the situation, considering it has a quick shot on there.

So should I try the 45 pilot? Remove the o-ring mod? Or do I need a smaller leak jet? Thanks!

[William1]

All you need to to do now is tweak the AP timing screw. Turn it CCW 1/2 turn and test ride.

The QS2 does not have an adjustable leak jet. So you have a fixed 55 in. Most have good luck with one between a 60 and a 40, so a 55 should be Ok.

[Luigic81]

ok, is adjusting the ap timing screw still going to have an effect even though It is o-ringed together with that little black part?

[William1]

The oring removes slop. The timeing screw is when the squirt starts in relation to the slide position. Two different things.

[Luigic81]

ok thanks I adjusted it turn 1/2 CCW, about to test ride it in a few minutes

[Luigic81]

that worked thansk!! I ended up about 3/4 of a turn CCW from where it was, now I just whack the throttle at any rpm range it the front wheel points to the sky ?

[William1]

Disgustingly simple, isn't it?

[Luigic81]

yea, and thank goodness for yamaha and the single spar frame, becuase you can make all these adjustments without removing anythign from the bike, my buddy's 07 kx450f you can't even see the carb behind the twin spar frame ?