Experience w/ Mercruiser engies

[zaffo oxnard]

I have always been a diesel boat guy, but am downsizing (kids, wife, time, etc.) and am looking at a boat with a Mercruiser 5.7 Carb engine. Will be used in salt water. Found a boat with shaft drive - won't even mess with outdrives. All the gas advice I get is to go with Crusater with full fresh water (even exhaust riser) cooling. There are tons of Merc. out on the watter, but most of them that I have seen have been getting towed back to port (just what I've seen, just like with Kawasaki jet skis - the Yamaha's are much more reliable).



Is there anyone out there who loves their Merc.s? Do you just have to replace risers and raw water pumps every 3 years, manifolds and exchangers every 5 to keep the thing running well. I do all my maintenance (oil, filters, plugs, coolant, etc), but are the Merc's inherently unreliable vs. Crusader / Volvo / PCM?



thanks

tony

 

[Johnny O]

Salt water is hard on everything from everybody. Flush it a lot. They're mostly all marinized Chevy engines regardless. Closed-loop cooling accomplished two things, 1) no salt water hits the engine and 2) you run a higher temp thermostat and the engine is more efficient and runs better that way. Raw water cooling, you need a low temp t-stat because you absolutely do not want the water to boil because that will leave behind all sorts of crud that was dissolved in the water. Ergo, you're running full-throttle (is there any other way? :lol with an engine that has looser clearances because it's not got full thermal expansion. In salt water, I'd go for a closed cooling system.

 

[Tom Higbee]

Had a merc on a 30 footer...with outdrive....for 6 years...raw water cooling..no problems..sold it last year to go smaller and the new owner says she ran great last year for him and he can't wait till this year. 7 seasons no problems...

 

[Greg Hatch]

Got the 4.3 L merc on my SeaRay, no complaints (except that I wish it was the 5.7!!!)