New Exhaust-lost power

[hotrodbob]

Got the 200 running. Had good power with stock exhaust. Decided to keep stock manifold but added 2 1/4 exhuast and flow master 3 chamber muff.

Now engine wont rev and has lost power. Do I need to rejet?

Carb is a Holley 5200 from Stovebolt.

 

[MustangSix]

Never heard another case of this. The log exhaust is so restrictive that a new pipe and muff usually makes a positive difference.

Sometimes when you add headers, an engine can run leaner. Maybe this is the case with yours.

 

[hotrodbob]

Didn't add the header because after the hot coating was done it warped. Hit the idler arm bolts and was only 1/2 inch away from the starter cable. We could have reheated and bent it, but then I would have had to re-coat it.

What I also have now is a backfire through the carb when I try to open the throttle fast and open the secondary barrel.

Seems like the accel pump is not squirting enough. Gonna get into a 5200 adjust post or site to see how to readjust it.

Just checked timing. Set it at 8 deg. btc. Idle is just low enogh to light the GEN light. Nice idle with the isky 262 cam.