Is my '74 90HP Chrysler pumping water properly?

I am the new owner of an old boat ('74 Chrysler 90HP). My first trip to the lake was cut short because I wasn't sure the motor was pumping water properly. At idle and speeds just above idle you can see a nice jet of water spewing out, however, by the time you reach 1/4 throttle or so there is no evidence of any water being ejected. Is this normal or do I have a bad water pump?

Re: Is my '74 90HP Chrysler pumping water properly?

Are you talking about the water coming from behind the leg? If so, this is for pressure relief when the boat is not moving as the exhaust is pushing against the water to get out of the snout behind the propeller. As the boat moves, it creates a low pressure area in the snout area allowing the exhaust and water to run freely. That is why you usually see more water spitting from the leg at idle than you do at high speed.

If you don't know when your water pump was replaced, it is a good idea to replace it as this is one area you don't want to have an unknown. They should be replaced every 2yrs in salt water and every three to five in fresh water.

John

Re: Is my '74 90HP Chrysler pumping water properly?

Thanks John! I suspected this was the case and now you have confirmed that. I'll get that pump replaced and get to some boating and fishing!