1997 Yamaha 70

by Kent
(Beaumont, Tx, USA )

I had carburetors rebuilt a year ago. I immediately took it out and ran boat in river. When I first put it in the water and take off, it runs great. When I stop at sandbar and sit for 10 min, 30 min or hour. I restart engine and starts fine but then when trying to plane, it runs like plugs are fouled. I use fresh fuel only, I actually changed plugs on sandbar and it still has no power. We idle back to ramp, I can take it next day and it runs great until it warms up and you shut it down. Is there something that has to do with electronic timing after engine is warm? I have changed fuel line, new tank, plugs.