Hello,

I've been poring over repair manuals during the past weeks and still can't definitively decide what is keeping my engine from starting. About a month ago I switched from a "C" to a "D" cam in my 142. While I was at it, I replaced the fiber timing gear. When installing the new gear, I noticed the crankshaft gear dimple and camshaft gear line did not align, so I rotated just the camshaft by hand until it did. I set the valve lash and timing marks according to the Haynes manual. With the crankshaft pulley mark set to +10 degrees TDC, the rotor and line on the distributor housing point roughly to spark plug #1 (imaginary 45 degree line from rotor to plug #1). Wires are ordered 1,3,4,2 counterclockwise starting with the tower that the rotor points to at the 0 degree timing mark. I've seen a good spark from the coil and each spark plug (checked one by one) as the engine turns over. Carb is delivering fuel and occasionally backfires when accelerator is pumped vigorously. Engine turns over freely via hand or starter but does not fire at all despite varying timing from 0 to +20 degrees advance.

So spark and fuel are present but perhaps timing compression is amiss. When I pull spark plug #1 and plug the hole with my finger, I do not feel any air escaping as I approach and move through the TDC mark on the pulley. However, when I approach and move through 180 degrees from the TDC mark, a good hiss of air emerges from spark plug hole #1. Could it be I buggered something up when I rotated the camshaft alone a month ago? Do I need to remove and re-align the dizzy or simply change around the spark plug wires? Or did I miss something else?

Thanks!