A two for...
Hey Barry,I too have a Venture 21 (but 1977). The lift you have attached to your back stay was a factory deal. The weight of your sail and boom isn't hurting anything by keeping it this way. As a matter of fact, the one plus is that it keeps the boom from swinging back and forth while motoring and knocking someone in the head. I still use mine all the time. However, I also installed a very simple alternet topping lift, but as noted in other replys, it must be connected when the mast is down. Simply attach one end to the mast head and the other to the end of your boom. Have it just tight enough that it holds the boom at your desired height but will automatically become slack when you raise the mail sail. No other adjustments are required. I use this one when I need to swing the boom out of the way while moving around the cockpit. We have small light boats and don't need all the other "normal" stuff that larger rigs require.Remember, keep it simple.Good sailing,Bob