2) Ammunition. Since it's an inertia driven gun, many suggest running some hotter loads through it to start. I picked up a few boxes of:
a) Winchester AA Lite Handicap Target: 7 1/2, 1oz, 1290 (3 1/4d) fps - Expensive
b) Remington Game: 8, 1oz, 1290 (3 1/4d) fps - Cheap (dove on the front of the box)
They actually tell you not to use the 1 oz loads. I just bought a Monte a month ago. I have shot 1 1/8 loads and 1 1/4 oz loads through it with no problem. For Sporting Clays I have been shooting Federal target loads 1 1/8 oz 7 1/2 shot with absolutely no problems.
I'd take those cheap 1 oz dove loads you bought and shoot them to see if it cycles. I expect if it's cleaned and lubed it should function properly. If it does not, get a couple boxes of 1 1/4 oz loads and run them through the gun, then run the 1 oz loads through and see if the situation improves.
My brother's SBE would not cycle the Winchester Super-target 1 oz 8 shot loads at the clays range. But after we stripped it, cleaned and lubed it, it would even cycle these light loads. Me, I'll stick with the 1 1/8 oz target loads.