Getting the hang of the new site - looks snazzy!
I'm trying to fix a poor running condition, and would like some suggestions, please.
Engine starts from cold, goes up to ~2500 rpm, oil pressure is 60psi, stays around those revs until the temperatures rise, the water choke opens up the top butterflies, and then the revs fall to around 1000rpm but then go up and down every few seconds between 1000 and 2500. There's also some missing: the engine is shuddering a little in its mounts. Oil pressure is around 45psi at this point. Water temperature in the bottom third of the gauge.
Recent changes I've made:
1) new plugs gapped to owner's manual specs
2) valve clearances all set to 0.007 (cold engine)
3) static timing set using TDC mark on camchain sprocket with distributor rotor pointing to #1 plug
4) new valve cover gasket
5) new 20w50 engine oil and filter
6) removed and cleaned carb, replaced with idle screw bottomed out then backed out 1.5 turns
7) removed and cleaned mechanical fuel pump
8) replaced fuel filter between pump and carb
Once the engine is warm, I've tried loosening the distributor and slowly rotating it this way and that to try to improve the running, but no luck.
I feel like I may have missed something, or made some stupid error, so even the most basic advice is welcome