mosesw

Quest,

Have you had any over heating issues?
No, I have not had any overheating. I just had the water pump rebuilt and the impeller replaced before this last trip out. If my temp gauge is accurate I am running pretty consistent around 160 degree.

Do I need to order from Mercury? I called NAPA and gave them the part number 27-863112 gasket and 862998 Valve, Idle Air. They were able to find the parts. Do they cross reference correctly per your experience? Difference in price NAPA 68 dealer 140 something.
Thanks.

TWIN-SPINS

you do not have to buy from mercury,,,a parts store iac will work

Questofpower

Like twin spins says, the napa one will work. I didn't replace mine with the one from napa, but I have read a lot of people on here that have. It should work just fine, I think I read once that the napa one is actually for a ford motor, but as long as the part crosses it should be just fine.

mosesw

IAC is ordered.

I was talking to Mercury Product Support, below are possible issues they think it can be. In their opinion it is not the IAC as this should come up on the diagnosis (I am replacing anyway / on order)

Fuel problem / pick up / Anti Siphon Valve
Shift switch adjustment

Shigger1

Those codes show up on 90% of the boats rigged.

Questofpower

Shift switch would cause it not to start; however, it also would not crank over if that was the problem. I think yours would crank over. It could be a fuel problem, if it was a pick up issue, try and remember if the problem changes with the amount of fuel on board. Meaning maybe the pickup tube is cracked and sucking air for example, but it only does that with a half tank or less. I just think if it was a fuel issue there would be other symptoms. Like hesitation, motor cutting out at full throttle etc. Taking what you told us that the problem seems to be worse slowing down, coming back to idle I really think it is some kind of problem with the IAC. I am curious if this does fix the issue, I really think it will.

mosesw

Quest,

I hope the IAC does fix the problem. I get the part mid next week, and then I will be going out that weekend. So I will post after my trip next weekend and let you guys know how it went.

Thanks again to everyone for your help!

mosesw

Hey Guys,

I was able to find this online and they carry several different parts for a variety of mercury / marine engines, and much
cheaper than the dealer / manufacturer. At the top menu bar select "Marine" and then you got it from there.
http://www.rockauto.com/

JETDOC

If its still quitting, check the wiring harness under the ecm on the aft side. Alot of 496's have the harness too close to the bracket causing the wires to chafe. Saw a thread last year for the same type of issue & his wiring was chafed to the metal. I added clamps & snake wrap on both of mine to prevent

38fountained

Reckless can I send you a video of my 496 problem.... Its sounds like an exhaust leak but hard to locate. Definite guardian when attempting to accelerate. 38fountained