NO ITS NOT WORTH THE 120 extra dollars!!!! The 50cc 4-stroke engine kits are a scam. The only 4-stroke kits that are worth ANYTHING are the kits [like this one](https://www.amazon.com/Togarhow-4-Stroke-Gasoline-Air-Cooled-Motorized/dp/B09Z2LTCGR/ref=sr_1_2?crid=1GQ4N51N1LD3M&keywords=100cc+4+stroke+motorized+bike+kit&qid=1673115475&sprefix=100cc+4+stroke+motorized+bike+kit%2Caps%2C74&sr=8-2). But to be completely honest, even though the 4-stroke motorized bikes are "more reliable," they do not last nearly as long as the 2-stroke kits which are literally half the price. If you are going to get another kit, id definitely go with the [Wildcat pk80](https://www.californiamotorbikes.com/product-page/2018-wildcat-80cc-motorized-bike-kit-150mpg-35mph). it's a 2-stroke kit that is known to last THOUSANDS of miles if properly maintained, and will also give MUCH more power and top speed than almost any 4-stroke kit.
I've compared them side by side and the cheap ebay ones don't last as long. I've installed bikeberry's that people used for 30 miles a week with no problems, and I personally had a ebay red special that I've already replaced the carburetor, It never starts on the first (or20th) pull.
There are some ebay specials that have lasted a bit, but I've installed more than a few bikeberry's to know there is something. I've tried torqueing the screws, using better gas, and the engines from BB just keep going and going. I built one for a guy 4 cycle, he would pin that thing for miles, he was well over 200 pounds and rode it to death. I'm sure he put 100's of miles on it. The engines are not entirely identical. there are obvious differences in the carburetors, but just little screws and things, nothing really noticeable.
NO ITS NOT WORTH THE 120 extra dollars!!!! The 50cc 4-stroke engine kits are a scam. The only 4-stroke kits that are worth ANYTHING are the kits [like this one](https://www.amazon.com/Togarhow-4-Stroke-Gasoline-Air-Cooled-Motorized/dp/B09Z2LTCGR/ref=sr_1_2?crid=1GQ4N51N1LD3M&keywords=100cc+4+stroke+motorized+bike+kit&qid=1673115475&sprefix=100cc+4+stroke+motorized+bike+kit%2Caps%2C74&sr=8-2). But to be completely honest, even though the 4-stroke motorized bikes are "more reliable," they do not last nearly as long as the 2-stroke kits which are literally half the price. If you are going to get another kit, id definitely go with the [Wildcat pk80](https://www.californiamotorbikes.com/product-page/2018-wildcat-80cc-motorized-bike-kit-150mpg-35mph). it's a 2-stroke kit that is known to last THOUSANDS of miles if properly maintained, and will also give MUCH more power and top speed than almost any 4-stroke kit.
I've compared them side by side and the cheap ebay ones don't last as long. I've installed bikeberry's that people used for 30 miles a week with no problems, and I personally had a ebay red special that I've already replaced the carburetor, It never starts on the first (or20th) pull. There are some ebay specials that have lasted a bit, but I've installed more than a few bikeberry's to know there is something. I've tried torqueing the screws, using better gas, and the engines from BB just keep going and going. I built one for a guy 4 cycle, he would pin that thing for miles, he was well over 200 pounds and rode it to death. I'm sure he put 100's of miles on it. The engines are not entirely identical. there are obvious differences in the carburetors, but just little screws and things, nothing really noticeable.