Bajadave04

Boat has 2 496 mag HO motors. The one motor is has a tick in it. Sounds like the top end. Also. 3 out of the 4 silent choice cylinoids are not working / making a lot of noise. Is there any common problems with these so I could fast track the fix. Thanks !

Keith Atlanta

What oil are you running? Every 496 I have ever owned ticked a idle. The lifters are noisy. Oil choice makes a big difference. Run 20-50 and it will probably go away.

Replace all the solenoids on the silent choice. Or put in slip in mufflers. I personally dont like silent choice, it was always problematic on both boats that had it.

BUP

iTrader: (9)

You need to post your year model and engine serial # 's to help with the problem.

Mercruiser has SB's thru out the years and could be listed in the SB's to what your problem is. For 1 example, early 496's that had certain engine serial #'s had bad / wrong push rods installed - they needed to be changed out and a big SB was brought forth to all Merc dealers back in the very early 496 days. That's just one example of the many SB's that are put out by the OEm's.

SB = Service Bulletins just in case anyone did not know.

I will say it again a 2001 496 is not the same as 2004 496 and a 2006 496 -is not the same as previous 496's a 2008 California 496 is not even close to any other 496. and a 2010 496 is not even close to any other 496 except the California 496. that's the way it is. .THIS IS ACROSS the board with most marine engines from the OEM's - they change thing and re engineer a lot of things thru out the years. just saying..

Also you need to post are these inboard series 496 with direct drives ? I would really wonder if you have bravo's on a Cobalt 34 footer.

Keith Atlanta

Yes, its a performance based boat. It has bravos.

BUP

iTrader: (9)

^^^^^^^ OK got thrown off as then we must be talking about the Cobalt 343 model as now that I really think about it , I do not recall a 342 model Cobalt. Might be wrong but I do know the 343 was a stepped bottom and they even threw hp 525 as an option in that model. I know they a couple of models with that and one with Ilmors but not sure if the Ilmors were day 1 one installs.

OP might have a typo on the model. Understandable.

Bajadave04

Ok thanks for the info. And I appaulogize. I will get the serial number today at lunch. And yes it has a stepped hull. As well as bravo drives.

Bajadave04

Also another weird thing was. 1 out of 4 of the silent choice cylioids work. I checked to see if there was power to all the cylinoids and there is. But when you take the power from the bad cylinoid. And put it on the good one. Now it does not work ????

Bajadave04

0w067069 is the engine number. Thanks in advance.

Keith Atlanta

Maybe the flapper/diverter has too much carbon on it. Can you make it work by hand?

Bajadave04

The plug that goes to the silent choice cylinoid. There is a red white and black wires in the plug. All 3 have power to them ?? Should one of them not be a ground wire ? And yes I can open the diverted by hand. They sound awfully rattly