FORCE 120 HP THERMOSTAT REVERSED was an old l drive block

[noflyzone]

Can anyone yell me if it matters that the 120 hp block I just put in my outboard
has the thermostat reversed it was an older l drive block now its a 1990 120 hp
outboard , is the water flow different also , will it overheat

 

[pnwboat]

Re: FORCE 120 HP THERMOSTAT REVERSED was an old l drive block

Water flow is the same. If everything is working properly, it will not overheat. Someone just goofed up and installed the thermostat backwards?

 

[noflyzone]

Re: FORCE 120 HP THERMOSTAT REVERSED was an old l drive block

Water flow is the same. If everything is working properly, it will not overheat. Someone just goofed up and installed the thermostat backwards?

If you look in any parts site the pre 1988 blocks the thermostat is install in reverse possibly also water flow was
also reversed so my question is are is this compatible I am not sure,,, I removed the cover plate off the head
and the heads are also different , so I may have to find a thermostat that will fit in the small opening
of the 1988 block L drive ...

 

[pnwboat]

Re: FORCE 120 HP THERMOSTAT REVERSED was an old l drive block

Hmmmm maybe I'm missing something. Wouldn't be the first time! The diagram below shows how the thermostat is installed in all the 125hp/120HP motors both L-drive and regular outboards 1988 - 1995. With the exception of the spacer (item 6) in the earlier motors.

http://www.crowleymarine.com/mercury-outboard/parts/1470_180.cfm

Can you post some pictures?

Regardless, the water flow through the block is the same on all these motors. The copper colored heat sensor part of the thermostat should be facing towards the water supply as it is pumped from the water pump. In this case, it would be towards the carburetors.

The routing of the water in the L-Drive is the same as the regular outboards through the block, but a little different after it exits the bottom water passage in the head (an extra hoses to route it to the exhaust on an L-Drive).

 

[noflyzone]

Re: FORCE 120 HP THERMOSTAT REVERSED was an old l drive block

here is a diagram , I hope (heat motor) ( spring side points away from block )

 

[noflyzone]

Re: FORCE 120 HP THERMOSTAT REVERSED was an old l drive block

http://www.**********/parts/search/Merc/Force/1988/H1251A88A/POWER HEAD/parts.html#

zoomale link

 

[noflyzone]

Re: FORCE 120 HP THERMOSTAT REVERSED was an old l drive block

try again

 

[noflyzone]

Re: FORCE 120 HP THERMOSTAT REVERSED was an old l drive block

I can seem to post a link so its on boats dot net , I have tried several times
I am not trg to be rude , I meant I tried again .....

 

[noflyzone]

Re: FORCE 120 HP THERMOSTAT REVERSED was an old l drive block

I am going to remove the thermostat housing and see which hole the water comes out
I can not reverse the thermostat it wont fit with the spring towards the block
I may be able to use the old water cover anyway ...if the water comes out through the block first.
in the older blocks Its looks like it went through the water jacket first , spring faced away from the
heads , opposite of common sense , but may of worked ,, with the 130 degree thermostat instead
of a normal 143 degree ... I can also try a differant thermostat to fit spring side to the block
depends on water flow , I dont want to change the water cover if I dont have to it also holds
the head in place and I not sure if you are suppose to reuse head gaskets ,, Well at least
this is a rebuilt block none of the screws are frozen

 

[noflyzone]

Re: FORCE 120 HP THERMOSTAT REVERSED was an old l drive block

http://www.crowleymarine.com/mercury-outboard/parts/1256_100.cfm better image quality

 

[pnwboat]

Re: FORCE 120 HP THERMOSTAT REVERSED was an old l drive block

Well that's a new one on me. Shows you what I know! I still think it shouldn't make any difference. Worse case scenario, it overheats in which case you need to get a different head. Best case scenario, it works just fine. My guess is that it will work just fine.

Here's a diagram of the water flow. Water pump feeds the water to the base of the block and is fed to the exhaust cover on the left side. Then it runs to the top of the block to the left side of the water jacket around the cylinders. It flows down to the bottom of the block and up the right side of the water jacket to the thermostat. It goes past the thermostat (when it's open) and to the water jacket in the top of the head cover. It then flows down this passage to the bottom of the block where it exits the motor. I think that tube looking thing on the right side of the diagram represents the water passage under the head cover.



Strange, just noticed that the picture with the diagram shows the thermostat of a smaller motor but it looks like the spring part of the thermostat is pointing away from the block. Go figure. Learn something new everyday.

 

[noflyzone]

Re: FORCE 120 HP THERMOSTAT REVERSED was an old l drive block

Just a follow up , The 88 L Block in my 120 Hp Outboard (1990) , is running fine maintaining correct temp ...
The 88 t-stats spring faces away from the block , so I was concerned it was oposite of my old block
thanks guys for your input , First run ran great just a little low spead stalls ( carbs or idle ajust ) I will fix it next