My GX160 has a 1&1/2" opening, same as my 212 predator..... Great idea though. Highwaystar, hit up your local auto parts (orielys or AutoZone) and got to the small engine "section" before you send me the $$. Or a small engine/lawn mower shop. I KNOW I had a kart engine that THIS cap fit.... Just sayin..... Id rather have a new one if I can get it cheap,or just as cheap.... Its up to you, I can always just "hold" it for ya, if you wanna look around a minute. I promise it will be on "hold" till you tell me either way. I have had it for about 8 years, it aint going no where.... lol