Help with mercruiser 4.3

[Dieter]

Hey guys I have a 4.3 Mercruiser 2002 model four winns 180 horizon. I replaced the water impeller in the lower unit, and the thermostat this past weekend. The temp is still a little high from what i have been reading here on the forum, at idle it is 175 then slowly climbs to 180-185. Should i be worried about this? I just thought with new parts it would not get over 175 ever but let me know what you think. Thanks

 

[Bt Doctur]

Re: Help with mercruiser 4.3

are the manifolds and risers 11 years old still?

 

[Don S]

Re: Help with mercruiser 4.3

Get an IR temp gun and check the engine temp right next to the gauge sender on the engine and see if the gauge is reading correctly.

 

[Dieter]

Re: Help with mercruiser 4.3

I have owned the boat almost 2 years as far as i know they are the same risers, and Ok Don i will do that. I did notice when i took out the thermostat that the intake manifold had quite a bit of rust in it just FYI. Also could it be the circulation water pump on the front of the motor?

 

[Don S]

Re: Help with mercruiser 4.3

if you boated in salt or brackish water, I could see problems with manifolds and risers, but I doubt you boat in either in the FW area.

Did you replace the gaskets on the water pump when you replace the impeller? Get all the parts back on the pump correctly?

 

[Dieter]

Re: Help with mercruiser 4.3

Never been in salt water. As far as i know I put everything back like it was. I did it on my previous boat for a few years with no issues. Is there a easy way to tell if i put it back together correctly without taking it all back apart and needing new gaskets again?

 

[Dieter]

Re: Help with mercruiser 4.3

Just reading other posts and thought of a few things i might throw out here and see what everyone thinks. Could it be the circulation pump? Would it be worth removing the risers and checking them? how hard is that task I have never pulled them off? Just wanted to say that i read a thread about chunks of impeller clogging the power steering cooler and everything else but my impeller was not missing any rubber, possibly the previous owners impeller replacements?

 

[Don S]

Re: Help with mercruiser 4.3

Think about it. You didn't have a problem until you replaced the impeller. Now you want to blame it on a circ pump or a clogged manifold from a previous owner loosing an impeller. Do you really think that happened, or are you looking for a reason to not check what you did? You did follow the OEM service manual on replacing your impeller didn't you?

 

[Dieter]

Re: Help with mercruiser 4.3

No the temps were the same as before. thats why i changed the impeller and the thermostat. sorry i didnt clarify.

 

[Dieter]

Re: Help with mercruiser 4.3

Well I tested with a laser temp gun and the sender is correct compared to the gauge. So i moved on and took off the lower unit, my job on the impeller seemed fine i couldnt find any issues. But in pulling off the unit i found an exhaust flapper stuck at the bottom of the exhaust. I guess this is the problem? I had one side replaced last year by my mechanic so is this the other side?

 

[Dieter]

Re: Help with mercruiser 4.3

Can anyone tell me which exhaust shutters i need my engine # is OM354503. Thanks

 

[Don S]

Re: Help with mercruiser 4.3

807166A2 with one piece manifold, 807166A1 with 2 piece manifold/riser.

 

[Dieter]

Re: Help with mercruiser 4.3



First time loading pictures hope they are ok, these are two piece i suppose right?

 

[Don S]

Re: Help with mercruiser 4.3

Yes, you have the 2 piece, here is what the one piece looks like.

 

[Dieter]

Re: Help with mercruiser 4.3

ok well thanks again don. ill get em replaced. And it never says if i need to order one or two items, does $53 dollars for two sound right? or is that just one side?