I just bought an evinrude 25hp about a 1980 I belive and it wont start. The guy started it for me when I bought it. A month and a half later I started it on muffs, then I took it out and ran it, each time it started easily and ran well, and when I ran it on my 15 ft jon boat it was quite strong. The next day I took it out to the lake and it puttered for about 2 seconds right off then nothing, its got good compression, fuel is reaching the cylenders and I have spark. Is there something particular I should look at on this engine? Any ideas? Thanks