Force 85HP Water Pump - Thermostat

[fishthebay]

Hello:<br /><br />Fired the boat up for the first time today this season. Its an 85HP 1987 Force.<br /><br />It took about a minute or so for the water to start coming out of the tell-tale. Once it did, it was a very good flow.<br /><br />I did notice however that before the water starting coming out, the powerhead got hot. I assume it took a minute or so for the thermostat to open.<br /><br />First question - Is this normal for Force Outboards?<br /><br />Second Question - I notice always notice that water immediately flows good out of the tell-tale once the motor is started in the water, while on a hose it takes about a minute. Is this normal?<br /><br />3rd Question - How long should I wait to cut the key off is no water is coming out of the tell-tale when started with a hose? Like I said, it sometimes takes a minute, but the powerhead gets hot and then if starts coming out in a good stream and everything cools quickly.<br /><br />Final Question-<br /><br />How hard is it to replace the waterpump and Theromostat myself? I have never done it on my own, but took it to a mechanic 2 years ago to have it done. I found a good mobil mechanic that's cheap. What should this cost me for a mechanic to do it, or should I attempt it myself?<br /><br />Thanks guys.

 

[my new fishmaster]

Re: Force 85HP Water Pump - Thermostat

I would go ahead and change both the thermo and water impeller. I did my 96 75force without a hitch well I did forget to unhook the rev/fwr,neut,shift linkage do that first. Make sure when lowering the housing all the bolts have been removed some are hidden under zinc part. My outboard was the same I had small rocks and stuff in it go run without the thermo in and a bucket to get the crap out first.

 

[sho305]

Re: Force 85HP Water Pump - Thermostat

When the boat is in the water the pump is about in the water so it has water right away. I ran my 85hp Force in a tub and had to hold the hose on the intake and my hand on the other side to force water up there. Then it worked fine. Needless to say, not getting water in there right away chews that thing up, so I hold the hose on there. The exhaust housing at the top cylinder is cold when it has water, gets warm fast without. The tub had water just above the top of the prop, and it seemed to have a hard time sucking it up from that level when started dry. It might need a pump, I just got it.

 

[Jim Williams]

Re: Force 85HP Water Pump - Thermostat

Can you tell me where the thermstat is? I can't find anything in the manual or the internet in regards to the location.
Thanks, Jim

 

[john from md]

Re: Force 85HP Water Pump - Thermostat

Jim,

There is nothing wrong with your engine and you don't need to take the thermostat out.

When on the muffs, you do not get water to the pump until the engine starts running. At that point, the pump must pump air and water into the uptake line that goes to the exhaust box. This is what takes the 15 to 20 seconds before it comes out of the tell tale. If you put your hand on the exhaust box, it will start to get hot until the water hits it and then it cools down.

This does not damage your engine as the time interval is short. The reason that you get almost immediate flow when the boat is in the water is that the pump passages are submerged and filled with water. The hose cannot fill these passeges as it is compressing air as it is trying to go in through the slots. This allows the muffs to back off and water pressure escapes.

To change the impeller yourself, read the sticky at the beginning of the maintenance forums. The theremostat is located at the top of the head in that little square box that your telltail connects to.

Enjoy and stop worrying.

John