Engine power loss, won't go over 40 mph

[thelonewolf]

I replaced my 71 tranny and distributor  and its run. But my engine  has lost it. Pep.  She wont go over like 40. I  am at a loss. And in need of help.  Also the. Vacuum was changed too

[legomybago]

Sounds like it could be a thousand different problems here....
Start with checking for correct ignition timing. Look for vacuum leaks. I don't understand the vacuum loss?
Does the tranny shift through all 3 speeds? Maybe its stuck in 2nd gear?

[thelonewolf]

Sounds like it could be a thousand different problems here....
Start with checking for correct ignition timing. Look for vacuum leaks. I don't understand the vacuum loss?
Does the tranny shift through all 3 speeds? Maybe its stuck in 2nd gear?

nope all 3 gears. Work. And the vacuum was just changed out and the timming was done a few weeks ago

[Bnova]

So it has been running really well for a few weeks and then all of a sudden won't get above 40? 

What else is it doing or not doing?  Backfiring, surging, etc?

[legomybago]

Make sure your getting full throttle cable movement at the carb.

[Rickf1985]

"Vacuum was changed out"? What vacuum? the vacuum advance? Check the timing and if it is way off and you have not touched it then you may have lost a timing chain. Check to make absolutely sure you have the right firing order and are starting with the number one plug wire in the number one position in the distributor. Make sure the rotor will line up with the number one position in the distributor when on top dead center of number one. If it will not then the timing chain has slipped.