502 overheating! Help!!!
 

I am a first boat owner, with a 2001 Baja H2X Doug Smith Special Edition, powered with a stock 502. I've had it almost one year without any problems, until now. Approaching the dock after running it for about 20 min. @ an avg. of 4200 rpm., I noticed the temp gauge heading way up, then the alarm went off. I shut the boat down ASAP. Unfortunately, not being to mechanically inclined, I'm not sure where to start at a diagnosis -- sea stainer, pump, thermostat, etc?. I'd like to make an attempt at a fix myself if at all possible. Any ideas? Thanks!!!

Re: 502 overheating! Help!!!
 

Start by checkig your impellars

Re: 502 overheating! Help!!!
 

is the boat in salt or fresh water? I know in salt water i have to clean the intakes on my outdrive or my temps will start to rise because theres not enough water getting in. If your impellers starting to go you will have the same problem. Good luck.

Re: 502 overheating! Help!!!
 

Holy smokes I need to work on my docking skills, I am not anywhere near 4200 rpm when docking..
Kidding but was it OK after idling down? pick up some trash maybe? First thing I would look at is raw water pump, even if temporarily blocked it would get toasted.

Re: 502 overheating! Help!!!
 

disconnect your intake hose from your oil cooler check your cooler for debri inside of it with your finger, clean as needed, with the hose still disconnected start the engine and see if you have water flow, the flow should be as wide as the hose itself, next from the same hose back flush the system with a garden hose and start the engine again to check flow, if you still have nothing replace the pump, also when you remove the hose from the oil cooler if u find any rubber vanes at the cooler your pump is shot hope that helps

Re: 502 overheating! Help!!!
 

Thanks to all for the advice! This rookie boater/mechanic will take a stab at a fix and report back. Thanks again!!

Re: 502 overheating! Help!!!
 

I had this same problem and it was the seawater pump. I never let it get up to the point in which the alarm sounded, I just happened to notice it would run abnormaly warm at idle.

Roby

Re: 502 overheating! Help!!!
 

Replacing the empeller in the sea pump is an easy job. Do it youself. You will probably do it every year. $25

Re: 502 overheating! Help!!!
 

Where do you get an impleller for $25.00?

I do change mine ever year. I feel it is better when the weather is cold then when I am out on the lake. Since I started doing every year they look good when I take them out but I know as soon as I start a season with an old one I will be standing on my head changing it at the lake while everone is standing around watching me work