Hi everyone. It's been awhile since I've posted here, but I'm hoping you guys can help me out.<br /><br />I'm working on a mid 90's, 50hp, Merc outboard that belongs to somebody I know. The guy said the horn goes off when he is trolling and it only seems to be getting about 3/4 trottle. He wanted to know if I'd take a look at it. <br /><br />He said he put a new set of plugs in it, and that didn't make any difference(I don't know what made him think it would?). He also told me that the old plugs all looked uniform, but didn't say what shape they were in(clean, fouled, etc.?)<br /><br />I just wanted to get some opinions as to what I should look at first? I'm thinking I should check the plugs(even though they're new), possibly do a compression test, and check the impeller/water pump. <br /><br />A friend said I should check the head gasket. I briefly looked the engine over and I don't see a head, let alone a head gasket. The block looks like it's all one casting. <br /><br />Anyway, I'd appreciate any and all opinions that you are willing to trough my way. Thanks