Ok, I'm new to the forum, so I appologize if I violate some Forum rules. Let me give some background on my issue. Just purchased a Pontoon that had been idle for over a year. Boat came with a Johnson 48Hp, Black cover not sure about the year. I suspect 1996 only because that is what the seller told me. Got boat home put into the water and it ran very bad stalling out somtimes. I thought perhaps it was bad fuel since it had sat for so long. Boat had 1/4 of a tank. I filled it up put fuel stabalizer/additives and ran tank through. Did same with second tank with no improvement. Everyone I talked to said, carbs were the issue. I purchased to rebuild kits. I must say when I disassembled the carbs, the bowls looked very clean. Infact my initial thought was they had been rebuilt recently. Continued with the rebuild. During the carb rebuild I noticed that the adjustment screws were off by a full turn from the top carb to the bottom carb. Top carb was set at 2 1/4 out, lower carb was at 1 1/4 turn out. Boat was also consuming lots of gas. So I set both carbs at 1 1/4 turns out. Took boat to the lake and performance was improved significantly, however I still have an issue. You can be running along at full throtle and all of a sudden it is like someone reached up and pulled the throttle back to half speed. If I reach up and pull the throuttle back to idle and then increase the throttle, 9 times out of ten it will run fine again. But it will do it again in a fairly short period of time, like about every 5 to 10 minutes of operation. Compression doesn't seem to be an issue, since the boat will run very good when it wants to. My sons boat had a hard time keeping up, he has a 40hp Johnson. So any suggestions would be greatly appreciated. Oh also put in new plugs.
