Motor Build Trouble

[TCullen]

My setup is a motor from an 86' with a hydraulic roller cam and adjustable screw in rocker studs, topped off with a demon carb. I just installed a motorsport b303 cam and am having a couple of problems:

1. After 5 minutes of running, the headers glow red hot I thought there was no breakin for the cam?

2. After running for a few minutes, the primary bowl of the carb floods, but not the secondary. I've checked the needle bearing and turned it all the way down, but nothing's worked so far.

3. She backfires like an m-80 when it is shut off, fires through the carb and the exhaust.

Thanks for your help

 

[D.Hearne]

Headers glowing-- timing's retarded. Carb flooding, needle/seat sticking. Readjust the needle/seat to get the fuel back to the sight hole, then give it a sharp rap with a screw driver handle. How did you previously adjust the carb floats? Which 86 5.0 do you have and heads?

 

[TCullen]

my engine setup is from a scca autocrosser. its got screw in rocker studs, worked over stock heads and forged pistons.
timing was set with the vacume advance still connected. it was set around 25deg BTDC. dumb mistake, so that should clear up the red hot headers.
i've repeatedly adjusted the carb by screwing in the needle assembly, cleaned it out, sang it a song but to no avail. its been removed to check for debris and i found nothing. i'm thinking that perhaps the float might be stuck but then again, i'm new to working with carbs.

 

[D.Hearne]

Change the needle/seat assembly. The sharp rap with a screw driver handle usually dislodges any debris that would make the float stick. It's also possible to have a bad float that's sinking. Too much fuel pressure will sink one, but if the rear float's working, that's not the problem. Remove the bowl, adjust the needle/seat till the float's level with the bowl inverted and put it back on. With this adjustment, only a minor readjust may be neccesary once it's running.

 

[TCullen]

you were dead on. i switched out the needle assembly and now she runs like a dream. thanks for your help, you probably saved me at lease $300 in shop/towing fees