360 Backfires Under Load

Thanks for the replies. I put the timing light and vacuum gage on the small untimed port on the carb. Advanced the timing and went from 5 to 15, unplugged the vac advance hose at the metering plate and it dropped to 12, sort of bouncing around 10-12 pretty much around 11. Did not see much pattern or wild movement. The needle was not still, though. Dialed the timing back and went around the four idle mixture screws. screwing out the primary side dropped the vacuum. Seemed to like 3/4 out from bottom. I turned out the secondary screws and it seemed to pick up a bit. The all aluminum Avenger has four corner idle mixture.

I drove it and it seemed to do fine in first but the 1-2 shift brought on some backfiring. I backed it up and did the same thing a couple more times. Seemed ok in reverse downhill(LOL) and would be babied in first uphill.

More info- I put a BM kit in the trans using the mild settings. I have Hurst Promatic with a burned cable(F&%$) that has a hard time getting first. Drive is ok but the ratchet action seems too stiff to ratchet(shifter works fine without the cable on it, but I had a rough time finding a spot where my clevis would drop in at neutral. A lot of post talked about moving the lever to the rear of the trans and shifter in first but mine seemed backwards.) The Hurst info said do it in N. If I try and kep it in first it will upshift around 25.

It was hard starting first thing. After tuning it started without the choke. Oh and my old timing light died so I am off to get a new one and some transfluid.

:newb: