Starts up and runs for about 2 minutes then begins to run rough then finally cuts off. I have cleaned carbs 2 times. Put new plugs. Pulled plugs and top plug has a darker hue . and after running in high throttle around lake for 5 minutes kept cutting off and had to keep priming to get back on trailer. Any suggestions. Have read alot of posts and it seems that i made a bad choice of buying. Thought yam was a great product. Can anybody help it really pushes boat when it does run at mid to full throttle
Your words above
in bold are a good indication of where the most likely problem is located...the fuel pump. Depending on how you store your outboard, the only time when priming the engine is needed is during a cold start (1st start of the day). With a healthy fuel pump, no matter how many times you start and cut engine you should not need to re-prime engine after initial cold start.
See schematic below of your fuel pump, located center right in picture. Dismount the pump and check for leaks. If you've got a friend nearby, have them squeeze primer bulb as you look at fuel pump for leaks. If it leaks, replace it with a new fuel pump.
If no visible leak is seen, re-mount fuel pump. Take the boat back out on the water and run it. When it starts running rough, feel the primer bulb with your hand. You should feel flow running through the bulb as the engine is running. If the bulb is collapsing, that's indication #1 of a bad fuel pump.
If the bulb did collapse, now you'll get the engine started and run it again. But this time keep your hand on the primer bulb and don't let it collapse. As the engine continues to run, you prime the bulb keeping it tight (don't over prime, just till bulb is tight). Keep repeating this for a few minutes as the engine runs in the mid rpms. If the engine continues to run, that's indication #2 of a bad fuel pump. And you don't need a #3 to complete this troubleshooting. It's a bad fuel pump. Replace. Luckily they're not expensive.
