Wash, pare, core, and chop enough pears to make 3 cups of chopped fruit. Peel the orange, remove seeds, and chop the pulp. Place chopped pears in a large saucepan. Add orange pulp, pineapple, cherries, and lemon juice. Stir in pectin. Place on high heat and bring to a full rolling boil, stirring constantly. Add sugar, continue stirring, and heat again to a full rolling boil. Boil hard for one minute. 

Prepare boiling water canner and heat jars in simmering water until ready to use. Wash lids in warm soapy water and set aside.

Remove jam from heat and skim off any foam. Ladle hot jam into hot jars leaving a ¼ inch of headspace. Clean rims of jars before putting on jar lids. Screw the metal bands on finger tight and place in boiling-water bath canner. Process for 10 minutes.

Turn off heat and take off lid. After 10 minutes, remove jars and place on a rack or kitchen towel on the counter.  Allow jars of jams to cool down without moving. You may hear pinging…the jars have sealed! After 24 hours remove the screw bands and test seal by pressing gently on the lid. Store for up to a year in a cool, dry place.