Mercruiser 200/Crusader 185

[Ghost1972]

Once upon a time, in the 1960s and then in 1969 Crusader Marine and Mercruiser used the 292 in a marine application. My boat was not originally one of those, but the previous owner was a machinist and replaced his 250 with a 292 attached to an Alpha Drive, and set it up with a closed cooling system.

Just had the engine rebuilt, and am running a quadrajet on it. Looking for tips on how to maintain it.

[mongocanfly]

no different than if the engine was in a truck.....keep oil changed..tune ups are the same..plugs ,wires ,cap, rotor...

[GRADYS Performance]

Make sure you use ALL Marine approved components. Gas fumes and sparks do not mix well in an enclosed engine compartment. Fuel pumps, Carbs, Flame arrester air filters, Distributors, Caps & Rotors, Alternators and Starters are All Marine specific.

[Ghost1972]

Obviously, I'm looking more at engine cooling temperature since it's a closed loop system, could I get away with a 180 degree thermostat? Right now the engine is running under 155 degrees.

[mongocanfly]

does it have a thermostat in it?..if so you can check them on the stove in a pan of water with a thermometer to make sure its working properly ....

[homemade87]

Most all marine engines run from 155 to 165 temp . They are designed that way because of the stress a marine engine runs ( like pulling a loaded trailer up a steep hill non stop ) . 180 is to hot . Remember the coolant is not only cooling the engine but also the exhaust system . The marine electronics is designed around 160 degree temp . You start pushing into the 180,s and most likely see some detonation . I would suggest you run the highest octane gas you can fined also .

In case you are new to this there is a fresh water impeller in the lower out drive that needs to be changed( I change mine every 2 years) . It has rubber fins that will come apart( need to find all the pieces if one comes apart) and leave you stranded or a burned up motor if not caught in time . Check out utube , you will see what I am talking about .

[Ghost1972]

I've changed Alpha one impellers before. And I run 89 or 90 Octane (ethanol free if I can get it). Because it's a closed cooled system, the raw water from the heat exchanger goes to the exhaust. So I want to keep the raw water below 140. I bought Motorad High performance 160 and 180 thermostats to test. Probably go with the 160. The engine has been running rich, and the temperature has been around 150.

[homemade87]

Originally Posted by Ghost1972

I've changed Alpha one impellers before. And I run 89 or 90 Octane (ethanol free if I can get it). Because it's a closed cooled system, the raw water from the heat exchanger goes to the exhaust. So I want to keep the raw water below 140. I bought Motorad High performance 160 and 180 thermostats to test. Probably go with the 160. The engine has been running rich, and the temperature has been around 150.

I have found that the boat gauges are not that accurate . If you put the 160 in and run it that way I would take note at what the temp gauges says and use it for a reference . Dont take the gauge as what actual temp it is . I have never had one dead on . If I see the gauge jump 15 or 20 degrees or more I know its time to start looking for a problem . If not I dont worry about it .