Thermostat housing question

[docofthebay]

I am having the common overheating at idle problem (goes away at 1200+ RPM) that is apparently due to the weak springs in the check balls. I have replaced the impeller and flushed the lines clear and do get good water flow out of the raw water inlet line. I am changing the entire thermostat housing to the new style (old style is discontinued) and have a couple of questions. The sleeve on my old housing went on top of the thermostat (thermostat in first, then sleeve on top) but the instructions included in the new kit show the sleeve first, then the thermostat, then the top piece. This doesn't seem to make sense as there is a slight groove in the housing that fits the thermostat itself. Also the sleeve in the old system has some cutout areas for water flow but the new one is solid all around, is that correct?
Also the check balls in the t-housing have about a 1/4 inch gap or play in them, I'm assuming to allow water flow before any spring compression and opening occurs, or should they be just touching the housing and then spring compression allows for opening. Is this the correct adjustment for the check balls?
Thanks for your help

 

[SCORPIO]

I did this last year. The sleeve has no holes, follow the directions for installing the t-stat. I THINK it went on top of the brass sleeve. I tightened the nuts all the way on those springs. If they open too early, they will allow water to bypass the engine and go out the risers.
If your problem doesn't go away (mine didn't) check the hose from the lower unit to the bell housing. It can kink and cause low rpm heating. I replaced both of mine this spring and problem solved. The Merc hose is a little too long and will kink. Shorten it abit and it shouldn't kink, or do what I did and use 3/4" wet exhaust hose thats reinforced and it won't kink.

 

[docofthebay]

Thanks for the help. I'll install this on Friday when I go back down to the the Gulf. Maybe the oil will be not to bad and I can get out.