496 Mag HO with 400hrs
 

What should be done to this motor to keep it running problem-free with this many hours on it.
Thanks in advance.

Re: 496 Mag HO with 400hrs
 

I would think other than regular maint. it should still be running fine. I think corrosion is one of the biggest enemy of marine motors. With the closed cooling that should not be an issue.

Re: 496 Mag HO with 400hrs
 

Keep An Eye On Your Fuel Filters. I Have A Problem Now With A 496 That Has A Pop At Idle. As Far As We Can Figure It Might Have Something To Do With The Fuel Nowadays. Seems That The Methanol They Add Can Cause Some Serious Problems. Filters Came Out With Some Red Looking Sh-t In Them And Also In Two Injectors. Other Than That They Run Good. Anyone Else Have These Problems Yet?

Re: 496 Mag HO with 400hrs
 

pay very close attention to your exhaust manifolds....they are aluminum..I have seen some them replaced due to corrosion,,,,your elbows are stainless and they should last a while

Re: 496 Mag HO with 400hrs
 

Good Advice from fellow posters! As sort of experts on 496's I can just add, use good oil and filters, and follow the Mercury recommendations on service to the letter and use a good marine service technician familiar with the 496 and you should see 2000hrs easy!
Ray @ Raylar

Re: 496 Mag HO with 400hrs
 

Thanks for the advice. It is appreciated. I boat year round and I put those hours on in a year. I was concerned about valve springs and lifters needing to be replaced by now. I would rather not replace them if I didnt need to so I fiqured I would ask my fellow boaters. Thanks for the help.

Re: 496 Mag HO with 400hrs
 

Raylar : Use good oil and filters...

What oil and what filters would be the most efficient for that engine?

Re: 496 Mag HO with 400hrs
 

As for filters, my preferences are the GM AC Delco glass media filter, the Puralator and Wix gold series, but there are lots of others, excluding Fram. As for oil , avoid synthetics and stay with a quality 15-40 w that meets the GM Powertrain marine engine warranty requirements. There have been a lot of great threads here on the boards about various oil, but always keep in mind the marine application and not automotive results.

Ray @ Raylar

Re: 496 Mag HO with 400hrs
 

Ray,
There has been numerous threads on which oils are the best to the point of beating a dead horse. Why do you (Ray) say to stay away from synthetics?

Just curious on your thoughts.

Thanks,
Bill