While Mahesh lost 11-4 11-9 11-8 to top seed Mazen Hisham, Kush went down 11-7 11-7 11-3 to second seed Mohamed El Gawarhy.
The Egyptians dominated from the start, while both Mahesh and Kush let go of a lead in the second game. The Indians were unable to win a single game in the match.
"I am certainly disappointed that no Indian made the final but both boys certainly gave it all they had. In my view these two youngsters are the future of Indian squash," said national coach Cyrus Poncha.
"This culminates a good week of top class squash with 5 Indians reaching the quarterfinals - a record for us at the British Junior Open," he added.