You should watch the summoningsalt video about frappe snowland he explain in one part how to do a trick that can make a lap under 5 sec i think but that’s on the Mario kart 64 version.
Best trick to know is boosting. If you do a wheelie while holding down both gas and brake buttons it builds up speed. If you release the brake button while still holding down the gas, it gives you a speed boost. It’s important to only start holding down brake first after you are already moving because otherwise the bike will not keep going the same speed. It can also be done in the air but only on bigger jumps.
Also it’s good to check out the Moto X3M page on speedrun.com and the discord page which you can also find on speedrun.com. That’s where the top runners are and can help you out with any questions.
You can absolutely make it to the finish line. The world record for level 18 on coolmathgames is a 7.64 by me and the record on Mobile (level 28 in this case) is a 6.86 also by me.
Some I found through the moto x3m discord with other people posting it. Some of the others I have found through experience with playing the game. Level 22 was through testing to specifically find the fastest way to get out of bounds though.