My dad has a 73' 70 horse with magna power ignition. It's a 3 cylinder with 3 carbs. When it runs right it runs strong but it doesn't always run right. For the longest time he has had problems with it running OK for awhile and then losing power. He finally decided to go through the carbs and found a small chunk of rubber clogging the high speed jet in one of the carbs (don't remember which one). After that it ran perfect for some time but then began to have power loss problems again and the overheat buzzer keeps going off. He pulled his plugs the other day and #1 & #3 look normal but #2 is as clean as new. He thinks he has a bad plug or a bad wire, but I think maybe he got the #2 carb too lean when he went through them. I'm gonna go do a compression check for him this afternoon. Any other thoughts as to what may be the problem?
