Proper Jetting for 05 YZ450

Bike is ridden at 1k' above sea level....has a bit of poping under decel (air leak in pipe?)

The bike is completely original...where should my jetting be at?



I went one notch richer on the needle and backed out the fuel screw a bit(1/8th). It helped.

It has been from 35-45F temp here. I ride around 5000 ft. I had some backfiring going from 3/4 to 1/2 throttle so I changed to the 170 main. From 1/2 to no throttle cackled so much I thought I was dragging Janet Reno behind me. Talk about ugly. This was at 3 turns out with the stock 45 PJ. Switched to a 48 at 1 3/4 turns out and now have easier starting and only the occasional bark.

Still haven't needed the hot start.

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