400ex Backfire

[jakslap]

I ran my 400ex out of gas and before I did, it started to backfire. That common?

Will running high octane fuel do anything for it?

[GPracer2500]

Yes. Backfires are common as the carbs fuel supply runs out. The jetting goes lean as it runs out of fuel and that can causes excessive popping through the exhaust.

As far as fuel, I believe the owners manual specifies 91 octane or higher....maybe someone can confirm that.

[bwamos]

Originally posted by jakslap
I ran my 400ex out of gas and before I did, it started to backfire. That common?

Will running high octane fuel do anything for it?

Yes, it's normal.

No, running high octane fuel wont help you to stop running out of gas. (Sorry, I couldn't help it.) ;)

Just run premium pump, you'll be just fine.

[Choppers]

yes it says in the maual to run 91 or higher but in jacksonville we have 87,89,93 so i use 93.

[400exrider707]

I always ran 87 in my stock 400ex, I never even started using premium until I put an 11:1 piston in.

[05trx400exridr]

i took the spart arrestor out of my stock pipe and now if i make it backfire when its dark, i get a 20" blue flame comin out the back lol. it sounds like a gunshot too lol