Re: SALT BUILD UP IN MOTOR (HOW TO REMOVE or STOP)
Water pump is good, I had starboard motor pulled and cam seals replaced,riser gasket replaced and there is some rust inside riser and replaced thermostat, port motor is in the same condition, to be honest with you I don't know where or what a shutter is and what it does?
My motors are the Big Aluminum blocks with iron heads/aluminum manifolds with cast iron riser. I remember reading a post from Don.S that said risers are on of the first things to rust out, does this have any thing to do with a shutter?
Thanks Mark
Howdy Mark! Hows things in "The Nest"? (from a former Oak Viewian!)
Your risers are the only cast iron parts of your cooling system exposed to salt water. So they would clog much faster than other components.
If they clog enough (they're designed to clog) they'll decrease the total water flow through the entire (raw water part) cooling system. That will cause a slow increase in temp at higher power settings.
higher power settings require more heat rejection (removal) by the heat exchanger......less raw water flow will increase the temp of the salt water exiting the heat exchanger & risers, resulting in a higher build up of "salt" and other corrosion products. Also, the higher temps increase the deterioration of those shutters.
Sometimes the shutter will break or "fall" off and end up in the bottom of the transom exhaust pipe. if it's in small enough pieces, it can actually go overboard. Usually they just get stuck in the bottom and restrict exhaust flow, power and in some cases cause slight over heats.
If either of your risers are at all questionable, (clogged) you should replace both and if you cannot see the shutters, or they look a little burned or crusty etc, you should replace both.
You have blocking type riser gaskets that should also be checked (read:replaced) every few years. If they leak, you'll have salt water in the exhaust port area that WILL run back into an open exhaust valve when you shut down. If that happens back in the marina, after a great time out at the islands, and you don't run the engine that salt water will sit on top of a piston in the cyl that had the open exhaust valve.
If it sits there long enough, salt water on top of unprotected metal.............(you can do the math yourself!!)
Regards,
Rick
