Does the thermostat housing on the 4.3 Mercruiser have a "T" fitting that loops off to the risers? Mine seems to be blocked off, which I "think" means that no water can get to the risers until the thermostat opens up? Is this correct? Thanks!
Depends on serial number/vintage and if your setup is oem/factory or has been altered
Well, it's at the mechanic's at the moment, so I can't provide that info. And he's a bit puzzled by the setup, as he's never seen this before. I just bought the remanufactured engine from Michigan Motorz last year, so I don't know how things were originally set up.
Was the motor you purchased a bobtail (complete/fully dressed) or a just a long block?
It was a long block. Had another mechanic put it together and install, so this current one isn't familiar with how it came from MM.
Hopefully the mechanic that performed the long block r and r saved the serial number tag(s). In your case it's the best piece of info for folks here to determine what the factory setup was/is.
The issue is that the mechanic currently working on my boat is a bit puzzled by the setup. And basically, I was asking if some of these 4.3 Mercs had the T fitting (that normally would go to the risers?) blocked off, such that water only circulated to the risers once the thermostat opened? If so, I can tell him it's "normal"...
If that's your only issue your best option is to find a new mechanic. Any decent mechanic ought to have access to the proper oem specs regarding what they are working on
The thermostat on raw water motors is used in a mixing valve configuration
