Cut kumquats lengthwise, and remove outer rind. Set rind aside.
Combine kumquat pulp, peeled lemons and water in a large Dutch oven; bring mixture
to a boil, reduce heat and simmer, uncovered, 45 minutes.
Thinly slice kumquat rinds; place in a large Dutch oven and cover with water.
Bring mixture to a boil. Boil, uncovered, 5 minutes; drain well, and set aside.
Press kumquat pulp mixture through a sieve or food mill. Measure 4 1/2 cups of
puree into Dutch oven; add sugar and cooked kumquat rind. Bring to a full rolling
boil; boil 1 minute, stirring constantly. Remove from heat. Add pectin, stirring
until well blended.
Pour marmalade into hot sterilized jars, leaving 1/4 inch headspace;
wipe jar rims. Cover with metal lids; screw on bands.
Process marmalade in boiling water bath 10 minutes.