hey, I'm new to the fourm. I have a 61' Chrysler 383 that will not run right.All it does is backfire through carb. and exhaust. I have installed new timing chain set,points,condensor,plugs, wires,dist.cap,etc. with no changes. But uf you spray 1short shot of brake cleaner in the carb. it will crank and run fine all day. Crank it up the next day,all it does it backfire.I'm looking for ideas or someone who may have had similar problem. Car has had 3 new carbs and does the same thing.

 

A compression test is in order, sounds like valves.

 

Your 61 is probably a 361 motor. Make sure the choke is working. What happens if you pump the gas 2-3 time ?

 

i had a similar problem that was getting me for awhile. fresh motor. timing. wires. everything. cranked over fired up until it hit a certain point then shot flame through the carb and died out. thought it was a bent valve.
turned out the vacuum advance went bad and was messing with my timing. unplugged the vacuum advance, plugged it up and was fine from then on