bike cackling when backing off

[Fordskin]

My bike seems to have developed a cackling [mild backfire] when i back off down through the gears. Acasionally it overheats in the tight stuff but today it overheated very easily in not so tight stuff. Seemed ok after i rode it home although still cackling. The bike has 3000k's on it. Bought new uncorked with the power up kit installed. Always starts easy. I have heard on this forum that the pilot jet may be too lean. Why would this problem develop and not from new. Any takers? ?

[creeky]

Exhaust popping when decelerating is an indication that the mixture is lean, either lean jetting or possibly an intake air leak. Check your intake adaptor clamps. If you have an aftermarket hot-start, I have seen instances of air leaks in the tubing and the hot-start lever.

[roadcam]

with engine running, try spraying some WD40 around your intake manifold, carb base, etc ... if you have a vacuum leak, the engine will speed up as it burns the WD40 ..

[HawkGT]

Yup, sounds like either an air intake leak or maybe even a partially clogged pilot jet (unlikely if it starts easy and/or hasn't been sitting dormant for weeks).