comittiguy

Is it normal for the paint to get toasted enough on the underside of the exhaust manifold to flake off of the curved section where it enters vertically into the ECT riser section?
My bilge has a lot of flaked paint in it after less than 30 hrs use since new.

BUP

iTrader: (9)

I would have it looked at as the catalyst core might be getting too hot and or you are lacking cooling water in that jacketed area. All the emission related stuff on these marine engines has a warranty up to 480 hrs or 3 years whichever comes first.

FIXX

iTrader: (2)

Yep^^^^ i saw that coming..at the temperature those cats hold back i dont see anything sticking to them but ceramic coating which is what merc should have done in the first place..i would call customer service and pitch a b itch..

BUP

iTrader: (9)

And so many things can ruin the catalyst brick. A miss fire, high levels of phos & Zinc based oils, running out of gas, extreme lean and or extreme rich conditions, water reversion will kill it on the spot, even gasket compounds the wrong types and of course lack of cooling. Volvo Penta has reduced their MPI fogging gas soup mix but Mercruiser too date has not. IMO high levels of 2 stroke oil when winterizing over time will kill the brick.

pilotkeith

Have the same issue with major paint flake off a 2016 8.2 HO. Mercruiser has been ZERO help, anyone care to chime in with some advice?

BUP

iTrader: (9)

Poppet Valve restricted -

check valves restricted

too hot running manifolds

too hot running engine

raise your idle rpms at the throttle ( basically reduce long term idling ) as that when the heat builds for the cat as it was intended to do - hence why there is poppet valve(s) in the mix

pilotkeith

So are you saying that the flake is normal as merc is telling me? I have a 20 min plus ride down the no wake zone to the lake, pretty close to idle.

BUP

iTrader: (9)

when did I say that was normal ? like I said possible hot spots and the reasons may be the problems.

BUP

iTrader: (9)

the poppet valve is control by water pressure. if the engine and or manifolds is lacking water pressure then yes you prob have a too much heat in the manifolds / risers.

long periods of idle is less water thru the manifolds and risers so make sure there is not something restricting water flow on top of making it even less water flow to them and thru the engine when the poppet valve(s) opens. I do not have a 8.2 sitting in front of me but if I recall correctly I think there is 2 poppet valves for that app. again would have to look at it. I forgot - the 8.2 is somewhat rare anyways. Yes its started life in 2010 and still is very current but rare compared to other models.

pilotkeith

Well I had one issue that lasted all summer. While using the boat axies we lost control of the boat, port motor shut down and the stb did not go to idle when released, ending up in some paint damage. Had the boat looked at and serviced but no cause. Then had the boat make another uncontrollable move but luckily not by dock. Took it in for service again, no cause found. Finally after loosing the motor in the middle of lake michigan, the service mechanics found that the main wiring harness was mounded too close to the manifold and was partially melted and shorting out the system causing the issues I was having. I wonder if the shorted wire was causing some sort of irregular operation or overheat condition. Wasted an entire summer with a brand new 250k boat with terrible service from merc and formula. What kind of service check to you recommend to ensure all parameters are working correctly? Also is the paint flake a big issue, corrosion, loss of useful life, most of the flake is off the bottom.