Easy to determine as the coil packs mount on the valve covers.

Okay after some of me messin wit it and finally bringing it to a mechanic, we eliminated the possibility of it being an ignition problem.... he believes it to be a mal-adjusted valve, as the rockers were replaced when the engine was done.... Thanks for the input and i'll let you know if that is the final conclusion...

valves/rockers are not adjustable on a 496,I believe they get torque to 25lbs.

it does have 2 different length push rods for exhaust and intake,maybe you got those mixed.

1,8,4,3,6,5,7,2

496 Is 1-8-7-2-6-5-4-3,,,1357 IS PORT,,,2468 STARBORD

Joe, what did you find?

If you need anything feel free to reach out to me.

Crazy suggestion but check for a valve cover oil leak.. I've seen oil leak on ignition wires and cause either a pop in the exhaust or thru the intake. Another thing, is broke/weak valve springs can cause a pop... Broken plug will do it, so will a fouled spark plug...especially if an injector is leaking...or a valve hanging up..or even a hammered exhaust seat.

Is the engine turning up the proper RPMS?

In situations like this I've always found you need two people on the boat.. One person to drive, the other to check for symptoms.

Frank

For an update we ruled out ignition and anything with the rockers being installed incorrectly... Also did a compression test and that was fine, A friend is suggesting valve springs, or a bad lifter... The spring seems to make sense so that will be my next attempt

Frank, I may give you a call later in the week, Thanks!!

Do yourself a favor and install new spark plugs first and try it before you go digging into the engine, Also run the engine at dark and look for a light show, Even under the coils.

Good luck with it.

my 496,s where doing the same thing one spark plug was bad and the iac motor took a **** .

It was a fuel injector!!! Found it on this post!
http://www.offshoreonly.com/forums/d...ers-fyi-2.html

What a relief!!!