Thermostat springs - one or two
 

I have a 1989 454 Mercruiser engine. I pulled my thermostat housing to clean the housing and replace the thermostat - I'm chasing an overheat problem. When I looked at the springs that controlled the check values to the risers, it looked like they were broken. So I ordered 2 new springs.

The dealer supplied me with a package with 2 springs, one is a steel colored spring, the other is a red colored spring. Now I see that these two springs were installed on both sides (4 springs total). Is this correct? Or should the steel spring go on one side and the red on on the other and if so, which side?

I can't find any info on this in the manual...thanks for your help.

Boy, I don't remember two springs, I had a overheating problem also, I drilled holes around the lip of the stat and it helped. The best bet is the coolers are too small, that happened on a 1989 Donzi with 454s. I had to remove the stats in the summer or the temps kept climbing. Are you seeing oil or water temps? My water was fine, the oil is what took off.

Water temp is OK (140-150), I don't have an oil temp gauge. But I get lots of steam on both exhausts though its OK at idle. I was thinking that when the thermostat opened, those two springs might be stopping the flow to the risers - they get way too hot!!!

Its a long shot but I gota try something. Also I'm checking the outdrive for obstructions. Thanks for your help...Sam