2 blown counter rotation lower units. 4 lift actuators went bad. Multiple blown belts due to Pully corrosion on professionally maintained and operated boat. Quad 450 r on a 420 freeman after waiting 8 months for Merc to get us parts. After being down 8 months we got motors back up with full 100 hr services just to be safe.2 trips we now have an engine that turns off when we go from cruise rpm to idle. Code goes no were. 3 super charger seals leaking oil out of 4 engines. It's been a complete nightmare. 3 years of owning boat and have only been able to use it 2 trips a year in 3 years beacuse after the second trip every year the engines have had Nothing but problems. We have a quad Yamaha 425 boat with 2k hrs zero issues expect maintenance and engines still look brand new. It's so bad. Mercury won't do anything about it. But if you corner a nerc guy they will tell you they know they have major problems with that model.

Hi!

Thanks. I have now 300 hours on mine with zero issues. Need to be careful when warming it up to let the thermostats open up. Use more fuel than my Verdado 400R, but that's expected.

Sorry to hear about your problems.

Cheers Toffen

All of them.

Hi folks! New to the forum. Just purchased a QXSB with 450R engine. Is there anything I need to know about break in period? Do I really need to take it up to 80-85 mph? Also on first oil change did you do it at 10 or 20 hours. Thanks for your responses!

Cheers!

I changed mine after 5 hours when new. Have had no major troubles but I don't run in salt water and maintain gear case oil every 20 hours and the oil is beat up.

Joe