Why would you ever not rebuild a set of carburetors you got off of eBay and check the pop off pressure and everything and bench test them as well you're going to end up frying your back cylinder especially on a 951 I've been working on these boats for over 20 years and it you have to check every single thing make sure you do a fuel pressure check it will cost you an engine over a $2 part never install carburetors off of eBay without rebuilding them with Factory bhikkhuni kits