Almost 300 people have given money to an online campaign to provide funds that will help look after Mr Harris’ two young children, a boy and girl aged seven and five.
The 34-year-old, who was a three-time British Supersport champion, died following a crash on the second lap of the Superstock Race at the Isle of Man event.
The online account, set up by his family, said: “We have received many messages of support and are grateful that Karl was loved and supported by so many people.”
“His talent, courage and passion for motorsport was something that was a joy to watch for us all.”
“For many of you Karl was an athlete but he also has two beautiful children.”
“For their dad to be taken at such a young age means we would like to financially secure their future.”
“They will need some help to get started in their own lives, when they are old enough to do so.”
A total of 280 people had donated by Tuesday lunchtime, with just over £5,000 pledged.
An investigation has been launched into the circumstances of last week’s accident.
* To donate, visit Karl Harris