small backfire after rides

[D3structive]

I was having an issue earlier this season with backfiring and figured it was either a timing issue or a lean issue because my jets were a little smaller than then should have been. I'm running a K&N with outerwear and a white bros slip on. Im jetted to 42/158 3rd notch on needle and running pump 94. the timing is spot on. The bike runs great but once I kill it I get a small backfire out of the pipe...every time. Before I changed to the larger main jet the backfire was much louder and intense. Is this something I should be worried about? what typically causes back fires? could my valves be worn? I have less than 100 hours run time on it. also, is my 158 main still too small?

[81dasher81]

When it gets colder outside you need to richen it up a little... So I'd say try a 45/160 or 162.. You probly don't need a bigger pilot though, it just makes it start easier cold

[D3structive]

so your saying my backfire is from too small of a main jet? my pilot is fine I have no starting issues even in cold weather

[81dasher81]

yes, i'd go up 1 or 2 sizes

[Stickman400]

The jetting on my 450 is spot on and my 400 is stupid rich and they both do that sometimes after I get done riding. Is the backfire more of a "pop" or a "pub"? Kinda hard to explain it but mine is more of a excess gas getting pushed out instead of a pop.