Ford F-600 Engine Backfire

When I Say Serious Backfiring, I Mean An Eight Foot Long Flame That Burns For Five Seconds And Has Started Grass On Fire!!! It Emits This...

Can You Give Me Suggestions To Fix An Exhaust Backfire. It Only Happens At Idle Or When I Rev The Engine As It Throttles Down.

The Truck Has A 370 In It, New Carb. It Runs Out Pretty Good It Just Has Some Backfiring In The Intake And Occasionally A Big Backfire From...