I have a 98 p40hp 2 stroke motor. After going down the river a mile or 2, whether it be wide open or half throttle, the boat starts to slow down and sounds a little boggy. You can release the throttole on the tiller back to a certain point, almost a 1/4 throttle, and then you feel it buck, and then it regains power. It will act normal for another mile or 2, then the problem repeats. A boat mechanic supposedly fixed the problem by rebuilding the carbs, he said it wouldn't act up for him, but the problem is still there. I've noticed this problem for about 1 1/2 to 2 years. I've taken it to other mechanics and they haven't been able to duplicate the problem. I've checked resistance on all 3 coils, the top and middle coil register 3.35 to 3.30 ohms, the bottom coil would not give a reading. Also the top and middle spark plugs looked okay and were dry, the bottom plug was a little wet-looking.
I hope someone can help me finally resolve this problem, and I thank you in advance.
I hope someone can help me finally resolve this problem, and I thank you in advance.