1994 Mercury 175 HP Water Pump Problems

[Duran]

I purchased a boat that has a 1994 Mercury Outboard, 175 HP, serial #18510G00. This motor had not been used for 3 years and I am having water pump problems. I replaced the impeller and put it back together and it peed very little. Not enough to keep the motor from running hot. I took the pump apart and checked to see if I had put it together correctly and it was. I put it back together and it still peed very little. I can hook a water hose up to it and get water pressure through the engine so I know that it's open. The last owner told me it had water pump problems and he thought that there was another impeller at the top but I don't know about this. I'm stumped and right now I guess my only alternative is to replace the whole water pump. I would appreciate any help that I can get about this. Thanks.

 

[racerone]

Only one impeller on it !------Do a compression test, blown head gasket is a cause of overheating.

 

[guyjg]

Where did you get the SN? Can't find anything close to it.

 

[Duran]

Sorry, something happened when I edited my post. I did have it right and should have re-read it. The correct serial# is 0G001851. Everything looks good on this motor as far as mechanical. It runs great, just doesn't pee good. Have checked all minor problems.