[BarryB]

Hi Steve,

Recreate the problem. With the boat in the water, let it idle for 10 minutes, if the engine quits, at least you know it's not a flushing problem.

It sounds like a carb. problem.

You can order the Yamaha repair manual. It runs about $80 with shipping, or try to find one on eBay.

On my 70, there is a procedure to set the idle speed and mixture for all three carbs. There is probably one for your motor too. If you are going to tinker, you need a book.