Perhaps someone can provide an experienced view as to how much downhaul is too much. Keep in mind, I am sailing my H16, going fast, and loving it. But, I have never even seen someone else sailing an H16 (other than on video) nor do I have easy access to an experienced H16 sailor in person (I am working on this).
When I pull/set my downhaul, my mast bends very noticably and tends to then hook to one side or the other because of this downward force. Is this typical? Am I pressuring this too much? On one occassion, the shackle/clevis pin that attaches my main to my downhaul assembly suffered a significant bend in the little stopper pin which allowed the clevis/pin to rotate past the stopper bump and the main to break out and bend the whole shackle...(perhaps it was metal fatigue). I do not have a power dounhaul unit, but I have a 2 to 1 purchase through the downhaul ring and a cleat. I am also quite strong...could I be over-doing this? What should I be looking for when setting the downhaul, and outhaul for that matter?
Dave 
Sounds like too much.
Rule of thumb is to remove the horizontal wrinkles. That means lighter downhaul in light conditions and more when it gets windier.
Matt,
When you say "remove the horizontal wrinkles", I assume this is done on the beach (not on the water) with the mainsheet and traveller loose or tight?
Dave
I would normally downhaul on the beach, but make adjustment while on the water. It is always easiest to downhaul when the main is sheeted, so best if crew can do it. Racers loosen the downhaul at the weather mark and re-tension at the leeward mark.
Sheet the main while pulling the downhaul. Usually the harder you sheet the more downhaul will be needed. Light air loose, heavy air tighter.
New class rules allow a 6:1 too.
Thanks Matt,
That helps me quite a bit. As for the 6:1, I just ordered one yesterday along with some other stuff. I am hoping the power downhaul will make it easier for me to make changes and experiement on the water - especially while sailing solo.
Dave