Thermostat on 454 engine.... 18-1989k. My first experience...

[RandyJ]

This is the first time I've seen this arrangement on a thermostat & housing. The repair kit, 18-1989 came with two sleeves and 3 gaskets. Of course, looks like only one of the sleeves and one of the gaskets will be used. My question is... does the thermostat go on top of the sleeve, up in the housing or below the sleeve and on top of the intake manifold? I have my ideas but prefer your input....

 

[RandyJ]

Found the answer! THANKS UNCLE WILLIE!

 

[alldodge]

Note the top gasket as well
http://www.mercruiserparts.com/Show...USING(FUEL+COOLED+SYSTEM)+SN+0K147349+&+BELOW

 

[RandyJ]

Thanks AllDodge (I hope)... now I'm confused a bit. There was not a top gasket when I took out the old thermostat, there wasn't one with the new thermostat 18-3649, and there wasn't one with the thermostat service kit 18-1989k.... but I do see one in my catalog with the housing 18-1989. ... after looking closely the part number for the housing illustrated is not the same as any in my parts catalog, nor is it shown in my catalog tho' there are two that look the same. One is stainless steel (18-1989) and the other 18-3530-1 appears to be cast iron. It appears that Thermostat kit 18-3647 would have been the correct way to purchase the parts I needed. However, it does not come with the replacement sleeve. The original sleeve is metal but the two in this kit, 18-1989k, are plastic. One is blue and the other is white. The only difference I see in these sleeves is a bump which is an alignment mark, one bump is longer than the other...
One issue here is that this is a new replacement engine. The boat has been in storage for 2 1/2 years and until it was brought to me to work on it had never been in the water since the engine replacement. The owner says the new engine has had timing issues and nowhere near the power it should have. First thing I had to do was replace the starter just to get it to run...

 

[Fun Times]

To help find the correct parts, we'll need either the engine serial number and if that's not available then a year of the original engine may help as long as the new engine wasn't 100% complete drop in. A photo of the thermostat housing design should help a lot as well.

 

[RandyJ]

No Title

To help find the correct parts, we'll need either the engine serial number and if that's not available then a year of the original engine may help as long as the new engine wasn't 100% complete drop in. A photo of the thermostat housing design should help a lot as well.

Thanks Fun Times.... I'll take you up on that. I would like to know for sure the correct thermostat, gaskets, insert and any kit that should be used with this motor. The numbers I've found on the engine are T07071RK, on the bell housing there is a serial number 0F352290. I'm attaching a couple of pictures which may be of some help.

 

[Fun Times]

The 0F number is the serial number and your engine comes up to be an MERCRUISER TB5 ignition, W/PS, TWOPCEX, WORO, GEN V engine block 7.4L BRAVO - (1995) Serial No 0F352290 Model No: 474B110HS Parts catalog No: 90-82172392

You can buy the thermostat parts individually as seen with item numbers 3 - 6, http://www.mercruiserparts.com/Show_...F305000+%26+UP

Or you can buy a 160 degree thermostat kit Merc part number 807252Q5 or aftermarket part number 18-3648, http://www.iboats.com/mall/partfinde...n_id=974621859

Be aware that if you buy a kit, the sleeve (item 6) that you sometimes may need won't be in the kit.

Some EBay sellers try to add it (things) in as a more complete kit,
http://www.ebay.com/sch/i.html?_from...52Q+5&_sacat=0

Here's your complete parts catalog or you,
http://www.mercruiserparts.com/selec..._nbr=821723+92

You should have had a cork gasket inside the T/housing where the thermostat rests. Be sure the old cork gasket was removed and the new cork gasket was set in place before setting the thermostat down inside the housing on top of the cork gasket...The sleeve helps hold the thermostat down/inside. Then the base gasket with the 2 brass rivets needs to be mounted dry or the sensors may not work properly due to loss of grounding. http://www.ebay.com/sch/i.html?_odkw...06871&_sacat=0

I just looked up service kit 18-1989k, the only 2 items you can use in that kit is the white sleeve and the base gasket that shows the 2 rivets. Hope the rivets are there because with aftermarket it's a 50/50 chance. That kit doesn't look like it comes with either the cork gasket that you need for inside the housing or the O-Ring had you had the older design T/housing. You'll need to order the cork gasket separately to do this job right. http://www.iboats.com/Thermostat-Service-Kit-18-1989K-Sierra/dm/view_id.708212

Good luck.

 

[RandyJ]

Thanks so much. Looks like I have all I need except the cork gasket. May have it in one of my spare part piles .....

 

[RandyJ]

Spark Plug Gap.... just want some input. Everything I look at is different but the closest my Mercruiser manual comes to giving specs is a .035 ??? I see several things on the internet that say everything from .035 to .040, .045, and even .060. Should I be good with .035?... sounds like a normal chevy plug gap to me. Problem with this engine is that the boat hasn't been in the water in the past 3 years. It is very sluggish on take off, can hear a miss, but runs fast on top end. Myself, I'm betting on old gas and gooky stuff in the fuel system.

 

[alldodge]

A 1995 engine should be set at .035