I just resently purchased a PV544, trailered it home and started rehabing it. It kind of ran when I bought it, but not really very well and definately not drivable any distance. Aside from all the general replacing of fluids and rubber parts, I had to get the engine in driveable condition.
I gave it a complete tune-up removed and cleaned the carbs. I went to start it up and it fired right up, but ran rather rough and sputtered and backfired upon giving it gas.After rechecking all the wires,I readjusted the carbs, which made no difference. After several hours of once again removing, cleaning and resetting the carbs, checking timing, wires, etc. I stopped and decided to start from the beginning.
Long story short, I found that the rotor I had purchased was about 2 mil. meters shorter then the cap height, instead of the metal tab on the rotor hitting the metal wire pickups, it was riding just under the metal tab on 2 wires. At first I thought maybe I had the new cap on wrong, but after several different attempts at removing and replacing the cap, there was no difference in the way it ran.
I finally installed the old rotor (which appeared to be just mil.met. larger) with the new cap and it fired up and rans great. I have never seen this problem before and it really had me stumped for several hours, but luck was with me and the car seems to be running great now.
Thanks for reading.