Pineapple Sweet Potatoes

6 large yams (cooked and peeled) (or 8 small)
1/2 c brown sugar
3 Tbsp lemon juice
1 9-oz can crushed pineapple
1/2 c shredded coconut
1 c sugar
3 Tbsp cornstarch
1/3 c melted butter
1/2 c chopped pecans

Cut yams length wise in thirds and place in greased casserole dish. Heat together sugar and cornstarch in saucepan. Stir in lemon juice, butter and crushed pineapple. Bring mixture to a boil and cook 5 minutes. Pour sauce over yams, sprinkle coconut and pecans over yams. Bake 15-20 minutes at 350 degrees.