backfiring

[duke]

 im on my 5th fj so know a good bit about them,but i have a backfire on closed throttle over run .have removed carbs and basic cleaned.renewed o,rings to barb rubbers interface with head,stripped complete exhaust replaced port gaskets.+all others.so not exhaust leak,now im foxed where to go next.on new plugs,k&n filter (clean) engine pulls/revs out ok.???HELP!! 

[Mark Olson]

carb float level is too high.

[Flying Scotsman]

Carbs ignition or air leak.Most likely the carbs.I just went through my carbs I had a choke circuit prob.My float hieght were all over the place causing me to get no fuel at idle on #2 carb.Sound s like you may have the opposite problem where you get to much fuel.Go through and clean the carbs set the floats and sync the carbs  and you should be fine.A bad ground or lose conection could cause a backfire too.

[SlowOldGuy]

Or, cound be exhaust gasket leak.

DavidR.