But the real test for the teenagers' grass karts will be on Saturday when they race head to head in Invercargill at speeds of up to 70kmh against their rivals from the Southern Institute of Technology.
The Otago students will race two karts they have built this year, while the SIT students will only race one, so the odds of winning are in Otago's favour.
Win or lose, in the eyes of their programme manager Rex Turner, the Otago students are winners already.
Youth Guarantee is a government-funded programme which started this year aimed at ensuring teenagers not doing well at secondary school gained qualifications and skills rather than dropping out of the education system altogether.
Of the 18 students who began a certificate in automotive and mechanical engineering (level 3) with Mr Turner, only 14 are still there.
One has gained an apprenticeship and three have left.
"For guys who weren't enjoying school, to start a project in mid-February and still be there finishing it in mid-October is a huge achievement," he said yesterday.
At the start of their course, the students were put into teams and supplied with a 250cc motorbike engine, the plans for a two-seater grass kart and plenty of advice.
The rest they had to do themselves - cutting, welding, gearing, steering, machining and fabrication.
Yesterday, they were making the final adjustments before stripping down the machines ready to paint them.
The karts will have test runs today before students, staff and a fan club of family members head to Invercargill for the judges' scrutiny and race day.
With many technical obstacles during construction, Mr Turner said he had been impressed by the students' ability to "figure it out".
"There has been real change in their confidence ... Most of them have become problem-solvers."
He is looking forward to meeting more problem-solvers next year.
The Youth Guarantee course is continuing and Mr Turner will have 32 students in his course.
