Re: kiekhaefer mercury 7.5 hp haveing trouble finding info on the motor
If you are just going by the telltale it could be blocked up, have you tried clearing the telltale out first? These impellers have very small veins and tend to break, they should be replaced once a year to insure worry free operation. Carholme provided you a link, you need to drop the lower unit, remove the bolts/nuts holding the top pump housing on, remove the impeller and make sure you don't lose the key. When reassembling I use a zip tie to compress the veins to allow the impeller to drop into the housing. Once half the impeller is in the lower cup, cut the tie and push the impeller all the way in. If the water tube comes out with the lower, remove it and shove it back up into the powerhead then reinstall the lower. Drop the lower with the shifter in neutral and don't play it until you get the lower back on, the splines should stay lined up upon reassembly.
There may be 2 size impellers, unless you have the shorter lower unit it should be the larger impeller.
