7.4L thermostat missing parts??

[klawton55]

I have a 89 Sea Ray with a 7.4. When I got got it there was no thermostat installed. I installed one but believe it was in the wrong spot. I had put it on the intake below the housing because I saw no other way. It didn't work right it would not come up to operating temp until I would come to a stop and then it would only stay warm for so long. After looking at the manual in the sticky section it looks like there should be other pieces that go with it to install it in the thermostat housing (go figure that's why it is called thermostat housing).

So my question is where do I buy these parts? All that I have now is the housing and the thermostat. I believe that I need a sleeve and o-ring and of course the upper gasket.

 

[Fun Times]

Re: 7.4L thermostat missing parts??

Do you have the engine serial number handy?

Yes the sleeve and o-ring goes inside the T-housing.

 

[klawton55]

Re: 7.4L thermostat missing parts??

No I don't. The boat is at my dads house and up on blocks to do the bottom. I didn't think about getting the serial number. I can get a picture of the housing tomorrow if that would help?

 

[Fun Times]

Re: 7.4L thermostat missing parts??

No I don't. The boat is at my dads house and up on blocks to do the bottom. I didn't think about getting the serial number. I can get a picture of the housing tomorrow if that would help?

You will need to see if you have the new or old design Thermostat Housing,

http://www.mercruiserparts.com/selectSerailRange.asp?doc_nbr=7.4L+BRAVO++++GM+454+V-8+1988-1991

The link above is one of many places you can buy parts online, Get the part numbers needed and google them for best price, even iboats sell these parts at a good price. Hope this helps, Good luck.

 

[tpenfield]

Re: 7.4L thermostat missing parts??

Yup, probably the "sleeve" as shown in the 'old' and 'new' thermostat design illustrations. Those parts are plastic and tend to break when trying to remove the thermostat. If it is missing the thermostat 'floats' in the housing rendering somewhat ineffective.

 

[klawton55]

Re: 7.4L thermostat missing parts??

Thanks! I do have the new style and was able to order the sleeve. Thanks again for all the help!