If it wasn't for bad luck...

Well, after losing my block at 7000 miles and with a new short block with less than 1000 miles--this happens.

Didn't drive for 6 mos. Charged up battery to go for a short spin yesterday, and 3 blocks from the house, LOUD banging and a couple of backfires. Turned it off and called for a TOW.

Got home and pulled the Driver's
side valve cover to find one of my Crower 1.6 RRS had slide sideways off the valve stem.

Removed the nut and rocker; checked the push rod. Doesn't appear to be any damage.

So what happened? Is it possible that the mechanic who installed the heads on my new shortblock didn't adjust the rocker tight enough and it finally just rolled off the valve. Could a lifter bled down since I hadn't driven it for 6 months and have caused this?

Now what do I do: just put it back on and try to adjust it (it is an exhaust rocker)?

Has this ever happened to any of you guys? Am I screwed or is this just a minor fix?

Please give me some help here.

Thx.