The motor is a 1987 Yamaha 70hp. It will start and idle fine. When you take off, it powers up (@5200-5500rpm) and planes out great. After @ 10-15 secsonds power drops to @ 4000rpm (WOT) and will stay there for @ 20 secs and then it will start surging. The first time this happened the primmer bulb did'nt feel like it has getting firm when you pumped it. So, changed it, still no joy. But this time when the power drops off you can squeeze the boulb (@10-15 times) and power will jump back up to WOT, and stay there as long as you keep pumping. So I say cool, and change the fuel pump. Same problem, no change! And choking only made the problem worse.<br />Now, my question for all you guys of knowledge. Do I go downstream of primer bulb towards tank and start looking for problem or head towards the carbs? The carbs were rebulit @ 7-10 hours ago. Water sep/filter on motor is clean and in line filter is also clean. Any and all help is appreciated, fishing season is here and I sure don't want to miss it.
