Tappet noise

At least I think it's the tappets. It's a loud ticking sound coming from the engine. It's more pronounced with cold, but doesn't disappear by any means when it warms up. It's loudest when the engine is under strain in low revs (ie upshifting when I shouldn't, or taking off from start and not giving it enough gas). That's when it starts to sound like a truck starting, and I know it can't be good for the engine in the long-run.

It's been a long time since it's had a service and I think it's just a couple loose tappets. I want to try my hand at tightening them up but I have no idea of what position to put them in. I guess I need a tuning manual, but if anyone has the degree settings needed for an '87 honda civic (I think it's a DX), I'd really appreciate it. Any tips or information I should know would also be appreciated. Before I take the engine apart, does this sound like the problem?