07 yz450f jetting with akrapovic

Hi guys, I just picked up an 07 yz450f this past weekend. The guy i bought it from put a full akrapovic exhaust system on it and only rode it once with the new pipe and then it sat for a year and he sold it to me :banana:. He said that he never touched the jets so whatever is in it is what the stock set up is. I was hoping that someone on here has this exhaust system on their bike and they could share their jetting set up with me?

It seems to run ok, there is a slight backfire on the downrev sometimes. I just fired it up at night and noticed the headers slightly glowing red. This scared the bejeezus out of me, but from searching around I guess its normal? I can't really see it glowing during the day.

I am just running what looks like the stock air filter. There really are no other major mods to this bike other than the akrapovic exhaust.

Any insight is greatly appreciated!

The reduced light level makes this more noticeable. It's not unusual for the surface temp 2 inches downstream to reach 850 degrees in 30 seconds or so, and that would appear dull red on a clear evening 20 minutes after sunset.

Ok so I just rejetted yesterday I put in a 48 pilot (stock 45) and a 165 main (stock 160). I took it for a quick ride again and still got the backfiring on decel. Overall it feels better than before it is smoother now and was jerky before. I am thinking of upping the pilot to a 50. Do you guys think I should be touching the clip any? It is still at the stock position of 4. I am also getting a fuel adjustment screw that will be coming in this Friday will that help the backfire? I'm thinking I should hold off on the new pilot untill the new fuel screw is installed. What do you guys think? Thanks.

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