Re: motor bogs down at full throttle
I have a 1996 25HP Evinrude that I bought new in 1998. I have the exact same problem as you described. I will be cruising along at full throttle, then, without warning, and very abruptly, the motor slows down almost to a stop. After about a second it goes back to full throttle. It is very intermittent; sometimes it won't happen for weeks, other times it happens 3 times in an hour. Here's what I have tried: I cleaned and rebuilt the carburetor (twice), replaced the fuel tank, fuel hose, primer bulb, checked all electrical connections. I have tried bringing it to a so-called "Authorized Repair" shop. The mechanic told me I had carbon in the cylinders. He replaced the head gasket, charged me $105, and did NOTHING to fix the problem. I just took the boat out Tuesday for the first time this spring, and the problem is still there. I bought a new fuel pump yesterday. This week I will install that and try the motor again. This has been very frustrating! It's nice to know that someone else has experienced this problem. Keep me posted, and I will do the same.