Mercruiser 496 Mag Opinions

[BillK2632]

I'm looking at a boat that has a 496 Mag w/Bravo III drive and wanted to hear from anyone who has this package in their boat. I have had several Mercruiser powered boats with both Alpha I and Bravo III drives, so I know all the in's and out's there. More interested in hear about reliability, service and mechanical issues associated with the 496. Engine is closed cooling and has 520hrs. The boat is a 2006 Cobalt 250 (25ft bowrider) sold new by the dealer and stored in their dry storage. I would store it in same dry storage where my current boat is.

 

[CliffA]

I'm looking at a boat that has a 496 Mag w/Bravo III drive and wanted to hear from anyone who has this package in their boat. I have had several Mercruiser powered boats with both Alpha I and Bravo III drives, so I know all the in's and out's there. More interested in hear about reliability, service and mechanical issues associated with the 496. Engine is closed cooling and has 520hrs. The boat is a 2006 Cobalt 250 (25ft bowrider) sold new by the dealer and stored in their dry storage. I would store it in same dry storage where my current boat is.

'what 'u talkin bout Willis?'......didn't know you were getting serious about a new boat.....sounds very nice....hope it works out.....

cliff

 

[BillK2632]

Yeah - this boat has been there awhile, I've had my eye on it and decided if it was still around end of the year I would take a serious look at it. I think the main reason it is still there is because it has a Mercruiser instead of Volvo - Cobalt offers both, but the dealer there exclusively orders theirs with Volvos. They had a similar 240 Sundeck awhile back that I was interested in, but it literally sold in a day. We will see - love that little 185, but it really is too small for LKN.

 

[KevinC]

If it is a 2005+ it probably has the Cool Fuel 3 system. Some of those were problematic with paint flaking off inside and jamming in the injectors. Rumor has it that Merc is replacing them if you have a problem though - you would have to go through a dealer and pay for their labor.

They are basically the same as my 8.1s (just paired to an IO instead of a V-Drive) and while they are Fresh Water cooled the exhaust side is still raw water cooled.

-Kevin

 

[paulswagelock]

Had that combination for many years. Great combination for big day boats. Powerful, smooth, but a bit thirsty.
Eats spark plugs but everything else was normal IO maintenance.

 

[BillK2632]

Paul / Kevin - Did either of you have issues with the Cool Fuel III ?

 

[paulswagelock]

Sort of. My cool fuel module died on year 7 of use. I figured it was paint related. I replaced it and took apart the old one. Although it was painted inside, that I could tell it had not dissolved loose. In any case, I eventually replaced the injectors and the old ones did not have paint in them. Mine was a 2008 model year.

 

[Korkie]

Twin 496 mags Bravo 3 drives. Just hit 1000 hours. Reliable, strong and yes Thirsty. In a 2006 340. Cruises @ 29-30 mph, 48 at WOT. Jumps out of the water even with 12 adults on board.
Only issues - cool fuel mode paint issue. Changed them and had injectors cleaned, also pout in thru hulls with strainers to get more sea water preload. Were running a little warm (bravoitis) now a firm 160 no matter what load or speed. Plugs every 2 years.

 

[BillK2632]

Thanks for the feedback - sounds like the main issue with these is the Cool Fuel III / paint problem. I don't know if this has been addressed on this engine, but will need to find out. I am figuring with 520hrs they could not have had too much trouble with it, at least it has been run. Just starting to look at this point and if I buy a Cobalt from this dealer it is more likely to have a Volvo in it - of course I am sure they have their issues also.

 

[KevinC]

Paul / Kevin - Did either of you have issues with the Cool Fuel III ?

I have the CF2 so no - however a dockmate was having issues and I brought this to his attention. I was told that Merc paid for the part but he had to go through the dealer who would get paid for labor. From what I have read it does not effect all of them but who really knows. It's just something to keep in mind. I would also use it to my advantage if negotiating on a 496 w/CF3 that was not already replaced.

-Kevin

 

[KevinC]

... also pout in thru hulls with strainers to get more sea water preload. Were running a little warm (bravoitis) now a firm 160 no matter what load or speed. Plugs every 2 years.

Yes, forgot about this on the B3 my 8.1s come with thru hull pickups, These engines are reported to eat plugs so the 2-year maintenance is good advice (mine are being done this winter) and it is one of the first places to look when things feel wrong.

-Kevin

 

[Espos4]

The previous owner of my boat had the cool fuel issue at 230 hours which was when the boat was 8 years old.