changed from the cr10ek to the cr8ek yesterday started fine ran good never misfired what so ever . Then getting off the fuel still rpm high shifting down and bang shift down bang and bang again getting to 2nd i turned in home stripped it down again pulled the plug everything looked fine and dandy whipped it back togther ran it again with no more backfiring . just a question should i get back to the 10 ek or would it be wiser to jump to the 9ek for a coolerburning plug ? thankz

 

Thanks for trying , i got the question answered in another forum with someone who was having the same problem and it was figured out . we changed the plugs and adjusted the fuel parameters .