Mr Ude will set off from Cardiff Castle on his 24-hour challenge on Saturday, July 10, and will only stop for fuel and breaks.
The fundraiser will see him travel to Trafalgar Square in London, then onto Edinburgh, before returning to Wales on his Vespa 3 scooter.
Despite it being a daunting challenge for some Mr Ude completed the ride last year and raised nearly ￡1,300 for Breast Cancer Now.
Mr Use covered last year’s 956.5 miles, which saw him visit Wales, England and Scotland’s capital cities, in just 19 hours and 20 minutes.
Mr Ude said: “I am hoping to do it this time again in 21 hours or under my maximum time allowed, which is 24 hours, to make it a tougher challenge.”
He has set his fundraising target at ￡2,000 and has already raised more than ￡700 for the Wales Air Ambulance, which is now a 24/7 service and needs to raise ￡8 million every year to continue to save lives across Wales.
People can donate via Facebook here.
“I have chosen to raise money for the Wales Air Ambulance as it relies largely on people who donate, so I thought it had to be done,” added Mr Ude.
“The support I have had from my friends, family and the community has been amazing.
“I am very excited about this year’s challenge, and it can’t come quickly enough for me to set off on my run doing what I love, plus to raise money for a great cause.”
Watch: Man who faced ‘horrific’ year wins his dream car and ￡80K
’Lots going on’ at Fonmon Castle with new and improved attractions
This is how you can get involved with a concert for a worthwhile cause
Community fundraiser for the Wales Air Ambulance, Wendy McManus, added: “Thank you so much to Jason, who is passionate about raising funds for charity.
”We’re delighted that this year he has chosen our lifesaving service to benefit from his fundraiser. The Charity is now a 24/7 service and what a fitting way to raise funds for the charity by doing a challenge that Jason hopes to complete with 24 hours.
“We wish him well on his journey and hope the public continue to support him in his fundraiser. Thank you to everyone who has donated so far. Good luck and stay safe.”
There are many ways to support Wales Air Ambulance including online donations, fundraising activities and the charity’s Lifesaving Lottery.
Find out more at www.walesairambulance.com
Alternatively, a ￡5 text-message donation can be made by texting the word HELI to 70711.