Sprinkle all sides of roast evenly with tenderizer, using 1/2 teaspoon per pound of meat.
To ensure penetration, pierce all sides deeply at 1/2 inch intervals with long tined fork.
In saucepan combine remaining ingredients; simmer 5 minutes.
Insert spit rod through center of roast.
Adjust holding forks and test balance.
Insert meat thermometer.
Place medium hot coals on both sides of drip pan.
Attach spit so roast is over drip pan.
Turn on motor; lower hood.
Roast over medium hot coals till meat thermometer registers 140° for rare (1 1/2 hours), 160° for medium, and 170° for well done.
Baste last 30 minutes with sauce.