Petrol cap M45x4 90cc quad bike

thingiverse

I designed this in Fusion 360 to replace my missing cap for my kid's 90cc quad bike. So far, the PLA seems to have withstood petrol exposure and remains serviceable. The M45x4 thread size should fit yours if it matches; the next common size up is 55mm wide. I initially made a trial print in M42, which was incorrect, so I increased it to M45 after some experimentation. For a one-way breather valve and tube, you can order from eBay for a few pounds, but this isn't strictly necessary. The design includes a rebate for a rubber washer inside the thread, although some rubbers may be compromised by petrol over time. You could also use thick card or leather as an alternative. If you print it without the washer, expect slight leaks when using the bike. Print it flat to the bed as it sits on the quad bike; I supported the inside, but this might not be necessary. Use caution with petrol, as it's hazardous - proceed at your own risk. Maybe this will help someone who has lost their original cap.