overheat protection
 

For those of you guys that have damaged or blown your motor because your impeller went bad or overheated it for other reasons would you buy a relay kit that would shut off your motor if your temp got to hot? I was thinking about making them and selling them. Just curious.

Gaffrig sells a water temp sending unit that can be wired to an audible alarm if your water temp gets too high.... also available are water pressure switches and oil temp and pressure switches that can all be wired in a parallel circuit so that if any of them go "off limit" they sound an alarm. I had them on my boat and they worked great. Also had it connected to a light on the dash to let me know which engine had set off the alarm. Saved my ass one time when I blew a water hose off the pump and was blasting around Santa Monica bay at about 70-mph... boat was running great.. I would have had no idea the bilge was filling with water if the alarm hadn't gone off....

My stock 502 computer has an alarm also,and I also blew a hose off and I did not hear my alarm. The only that saved me is that the computer shut my motor off. It seems lik you read alot of threads about guys overheating and blowing their motor. Does the alarm you bought shut off your motor?

Nope.... didn't shut off the motor....but the alarm my boat had was so shrill and loud there was no way it could not be heard... also the light on the dash was quite large and bright.

Did you blow your hose off because of too much water pressure in the block?

Hahahahahahaha..... no.... I just didn't tighten the clamps enough :D

Lucky you. I threw a pressure gauge on mine and found about 50 pounds water pressure at about 50 mph, so then I had to change a few things around.

Yousah! 50 lbs! About the highest I ever saw mine was around 15 lbs..... and even then I put in larger hoses on the header drains.... I liked to keep it around 10 lbs....

On older motors without ECU's you can easily wire a relay into the alarm circuit to cut the ignition if an over temp. or low oil pressure occurs. Just tie in the relay coil (+) to the alarm buzzer power and (-) to ground, then connect the relay N.C. contact and COM contact in series to the ignition coil circuit (purple).

This will keep your motor from melting if you don't hear the buzzer while you are doing 70+.

Just my $.02

-Larry