Mercury 115 4 Stroke Guardian System
I installed a brand new Mercury 115 in my RIB three years ago & after 11 months and 100 hours the engine had a catastrophic failure after about 3 seconds of alarm warning of overheat. I do not drive the RIB hard & is regularly serviced by the dealer and is for cruising, not racing. Mercury replaced the power unit under warranty, but now two years later at 400 hours (300 hours on this power unit) the same thing has happened... catastrophic engine failure said to be due to overheating (a blocked water inlet by plastic bag???)... again, I only got 3 seconds of alarm and I immediately dropped the rpm to neutral and the same thing had happened. I thought the 'Guardian Software' was supposed to give more than 3 seconds notice of an overheat if that indeed is what happened)... Some are telling me that Mercury Engines are prone to this type of catastrophic failure & are best avoided... I am waiting for the engineers assessment of the damage, which looks like I will need yet another new Power unit (makes 3 in 3 years!)... would be interested in peoples views on this engine and the Guardian system that is supposed to protect it...
I will likely buy a whole new engine... not sure if I could bring myself to buy another Mercury though!...