95 yamaha 50 runs wide open for a few minutes then dies. With warm up lever up a bit runs fine

95 yamaha 50 2 stroke idles fine. When running wide open it will die after a minute or two. Starts right back up and will do it again. It has plenty of ventilation at the tank. When i kick up the warm up lever a bit it will run fine WOT. Any help is greatly appreciated. Thanks

sounds like a weak fuel pump

I may be wrong but that "warm up" lever should actually be a "start lever" that increases fuel to the engine and also actuates a choke at the same time. If it runs wide open with that lever raised with no problem you are running in a choked state that helps an engine that is running too lean. Buy 3-4 cans of carb cleaner (carb cleaner is cheap - Yamaha service is expensive) pull all carbs, break the down and blast away through every orifice you can find. Remove the tiny brass fuel jet in each carb and look through them, blast carb cleaner through the jets and see of they are totally clean. Any partial clog in a fuel jet will cause this. If there is anything carb cleaner won't clean from those jets get a piece of bare COPPER wire and run it through the jet orifice (copper is softer than brass so you wont score the inside of the brass orifice and create a scratch that invites future buildup). I say you have carbs that need cleaned.