I have an 89 Sea Ray 180BR which I refurbished last year. The original 4.3 V6 in it was kapput, so I picked up a Mercruiser 'bobtail' engine ) 4.3LX Gen 11 with a 4 barrel carb, that came out of a 96 Baja boat. The sterndrive on my Sea Ray is an Alpha One (the original). We totally refurbished the gimble and my boat guy checked over and replaced anything not right on the sterndrive. The boat runs fine, but I noticed the temp gauge wasn't working. Have checked the gauge and wiring and they are fine, but the temp sender looked worn out, so have replaced it with a new Mercruiser sender unit. I haven't had chance to check it out on the water yet. When I was removing the old sender, I removed one of the hoses to give me more wiggle room and noticed that some rusty corrosion on the pipe ends. Not maga amounts, but either it needs removing and a good clean or it needs replacing. This is where I'm seeking input.
I checked out Ebay, etc for thermostat housings and there appears to be 2 variations, the 860256A3 and the 860256A4. The A3 is Alpha and the A4 is Bravo. On one site (perfprotech) they say that 'because of water flow properties', the A3 housing should not be used on a 'Bravo engine' and the A4 should not be used on an 'Alpha engine'. The A3 is identified by ALPHA stamped on the housing top and the A4 has a part number stamped on the underside.
Now I know that the engine I now have had a Bravo sterndrive, but in my boat it is now powering an Alpha drive (my boat guy swapped the drive coupling to make it work).
My housing has nothing on the top, so I'm guessing I have the A4. Should I now be looking at changing this thermostat housing out for an A3? I don't want to, part with $150 to $200 for no good reason and as a newbie boater I don't want to be running the engine incorrectly. Does anyone know what these 'different water flow properties' are on the 2 housings? Outwardly they look identical.
Just to muddy the water further, I visited a site (offshoreonly.com) that has a stainless steel thermostat housing (yippee, no more corrosion)for sale for $190, which it says is a direct replacement for both A3 and A4! That appears to fly in the face of what Perprotech say.
I am worrying unnecessarily about the difference in the thermostat housing?
I checked out Ebay, etc for thermostat housings and there appears to be 2 variations, the 860256A3 and the 860256A4. The A3 is Alpha and the A4 is Bravo. On one site (perfprotech) they say that 'because of water flow properties', the A3 housing should not be used on a 'Bravo engine' and the A4 should not be used on an 'Alpha engine'. The A3 is identified by ALPHA stamped on the housing top and the A4 has a part number stamped on the underside.
Now I know that the engine I now have had a Bravo sterndrive, but in my boat it is now powering an Alpha drive (my boat guy swapped the drive coupling to make it work).
My housing has nothing on the top, so I'm guessing I have the A4. Should I now be looking at changing this thermostat housing out for an A3? I don't want to, part with $150 to $200 for no good reason and as a newbie boater I don't want to be running the engine incorrectly. Does anyone know what these 'different water flow properties' are on the 2 housings? Outwardly they look identical.
Just to muddy the water further, I visited a site (offshoreonly.com) that has a stainless steel thermostat housing (yippee, no more corrosion)for sale for $190, which it says is a direct replacement for both A3 and A4! That appears to fly in the face of what Perprotech say.
I am worrying unnecessarily about the difference in the thermostat housing?
