Prepare boiling water canner. Heat jars in simmering water until ready to use, do not boil. Wash lids in warm soapy water and set aside with bands.

Combine carrots, pears, pineapple with juice, lemon juice, cinnamon, nutmeg, and cloves in a 6- or 8-quart saucepan. Bring mixture to a boil over high heat, stirring frequently. Reduce heat, cover and boil gently for 20 minutes, stirring occasionally. Remove from heat and whisk in pectin until dissolved. Bring mixture to a full rolling boil that cannot be stirred down, over high heat, stirring frequently.

Add sugar all at once and return to a full rolling boil, stirring constantly. Boil hard for 1 minute, stirring constantly. Remove from heat. Skim foam if necessary.

Ladle hot carrot cake jam into hot jars leaving 1/4 inch headspace. Wipe rim. Center lid on jar. Apply band and adjust until fit is fingertip tight. Place jar in boiling water canner. Repeat until all jars are filled.

Process jars for 10 minutes, adjusting for altitude. Turn off heat; remove lid and let jars stand for 5 minutes. Remove jars and cool. Check lids for seal after 24 hours. Lid should not flex up and down when center is pressed.