Mercruiser Winterizing Questions

[BassinProf]

Hello, when it was time to fog my 5.0 MPI instead of spraying fogging oil into the air intake I decided to go with the service manual procedure of using a portable fuel tank with 2-stroke oil added. Two questions though -- I didn't get any smoking at all from the exhaust like I would have expected, is this normal? Second, I didn't notice that the service manual says to run it at 1300 RPM. I just let it run at idle speed, but for much longer than the 5 minutes specified by the manual. Do you think this could be a problem? Thanks!

 

[Scott06]

You would expect to see a little smoke but I wouldn't worry about it you'll be fine. The increased speed I believe is just to keep it from bogging down so no issue either. FWIW had engines sit in old cars for several years with out fogging, take the plugs out and run it on the starter to Get oil primed and run just fine.

I assume you drained the water from it if you are in a freezing environment?

 

[BassinProf]

You would expect to see a little smoke but I wouldn't worry about it you'll be fine. The increased speed I believe is just to keep it from bogging down so no issue either. FWIW had engines sit in old cars for several years with out fogging, take the plugs out and run it on the starter to Get oil primed and run just fine.

I assume you drained the water from it if you are in a freezing environment?

Thanks! Yes, I drained the water and then filled up the block with antifreeze through the coolant hoses. Thanks again!

 

[R055]

You'll be fine, most people don't fog because you engine will only be sitting about 6 months or less.

 

[tpenfield]

No smoke on my MPI engines during the fogging cocktail. So, no worries on your part.

Idle speed will still be fine . . . not sure why the manual specifies the high idle speed. I've done in either way and lived to tell about it

 

[NHGuy]

Weird that they don't fog down the air tract. On a a carburetor engine without sensors you can fog down the throat and it will oil the valves and the chambers. Fogging through the fuel is probably done on injection motors to keep the fog oil off sensors in the intake tract.
I stopped fogging a few years ago, but it can't hurt.

 

[tpenfield]

Fogging with a fuel/oil mix on an MPI does the same sort of thing . . . gets oil to the valves and combustion chamber . . . since the injectors are just ahead of the intake valves.. The main difference vs. a carb engine is not getting oil to the upper part of the intake manifold/plenum.