Looks just like the back of my old boat.... 496 Mag... turned out to be the battery was old & low voltage caused the motor to go into guardian mode..... just sayin....

Here I have pictured the new and old Intake Gaskets. The New Gasket is on the Left and Old on the Right. The Old gasket was plastic with a rubber seal. The New Gasket is Metal with rubber. The new Gasket is only 0.500mm thicker BUT, the metal areas are thinner than the Original Plastic surfaces. So this allows the rubber areas which are 0.500mm thicker to crush down even farther. Looking closer at the old gasket there isn't much compression area on the rubber. So it looks like once the Intake was torqued down with the old gasket it bottoms out on the plastic, not allowing the rubber seal to do it's job.

Motor is back together, however I need to wait until tomorrow to test as I did use (based on Raylar's suggestion) Grey RTV sealant in the corners where the gaskets meet the front and rear seals. I will put new plugs in it and take it for a ride, then do a plug check.

http://www.bradzgarage.com/velocity/IMG_0410.JPG

Curious to see if those gaskets make any diff.

Low -Psi:

I really recommend you take the intake manifold and using some good carb cleaner or solvent and compressed air and clean all the oil buildup out of the intake manifold. As you can see from some of the pics I posted it has a lot of nooks and crannies where a lot of oil will build up and it will take a long time to get most and by all means not all the oil run thru the engine. Remember this is a dry manifold with no fuel in it to wash out the oil as the injectors are port injectors and only spray at the backside of the intake valves.

DO NOT , I REPEAT DO NOT under any circumstances spray these cleaners or solvents into the intake after its on as they will become a bomb making scenario and can blow up the manifold and top of the engine from ignition of these vapors in the manifold!!

Just some more important information and suggestions here.

Best Regards,
Ray @ Raylar

I sprayed some carb cleaner in each runner and cleaned out with a rag, as much as I could. The intake is already on. I will be taking her out this afternoon to see the results. I will run it a bit, then switch to new plugs and see if they still get oil soaked.

So far the results look very promising. Took it for a ride with the old spark plugs first. I run it pretty hard for a bit then shut it down. Pulled the plugs and they look much better than before. The oil ring has almost disappeared from all plugs and that burnt brown color is gone. I also noticed my oil pressure Is now about 5 psi higher at idle and at speed. So it appears the intake was leaking a lot of oil...... Putting new plugs in now and will run it hard again and do another plug check. The transom does have some soot/oil residue on it again, but I expected that until all of the oil is blown out of the system. So far so good!

Here is a shot of the new plugs (I previously ran these in the motor and they got oil soaked). After about 10 minutes of run time, all of the oil on the ceramic has burned off and it is now white again. THe dark oil ring that was present at the base of the plugs is burning away as well. The intake gasket was definately the issue. Also a shot of the transom after running it very hard. What is pictured was much easier to clean. I expect the next time out i will see less, and it will be even easier to clean.

I have to give a shout out to RAYLAR!!! Without your suggest, I would still be chasing my tail. I am so happy I got this issue resolved... Anyone want to buy a 2003 Velocity 260? I am ready to move to a Center Console now.......

http://www.bradzgarage.com/velocity/IMG_0415.JPG
http://www.bradzgarage.com/velocity/IMG_0416.JPG

+1

Low -psi:

Glad to hear the oil burning problem seems now to be resolved and repaired. I pretty much new that was your problem based on the model year of your engine. I am just glad my considerable knowledge of the Merc 496-8.1L engine can help in situations like this . It's great to know your frustration and problem has been relegated to the past and you can enjoy your boating without such a mess on the back of your boat.

Best Regards,
Ray @ Raylar

I really appreciate this thread guys. After switching to unmuffled tips and running in a run this last weekend, my transom is getting oily soot too after running hard for a long time. Looks like I'll be putting new gaskets on also.