I finally started the plunger flash and its running hot. Both headers have blued after being run for about 2 minutes in the garage (with the door open). It revs soothly but back fires when settling down to tick over. It fires on kick over and runs for about 5 seconds then cuts out when cold. I have to do this several times over until it warms up. It then runs and gets hot. The plugs look OK. The timing was done before I put the head on, I had it spot on.
Any suggestions what to check first?
Stu