EXHAUST MANIFOLD GASKET REPLACEMENT

[scoobeb]

I talked to someone about this who owned his own shop and said he personally had worked on these outboards allot along with tons more of course and I asked him what he thought, he said he has never personally seen one fail in his lifetime and shouldn't unless owner neglect comes into play. He said just leave it be if it runs flawlessly no matter how old she is and if you want peace of mind just pull the bottom plug once a mth to Check for any water on the plug,that would be a good indication of a failed gasket usually,he went on to say he would bet the original gaskets would last for the rest of the time I own it and so on till it's retired. He said don't worry and just enjoy without panic. Works for me,just for peace of mind I will check the lower plug once a month,there is no problems with this outboard and I plan to keep it that way. Case closed, I will leave it be. I at least have the gaskets on hand if it does act up. Thanks to all for the helpful info.

 

[scoobeb]

Have had this gasket fail on a 93 20hp merc luckily it was an external leak.Not sure why it failed not corroded and was never overheated.Same problem with a newer yamaha mating surfaces perfect but break in gasket.How would one detect an internal leak?excessive steam?rough running?washed piston crown or plug?powerhead damaged by that point?So yes change the gasket the merc ones are cheap.Be gentle when removing bolts as you probably already know use a small wrench and if you suspect one is frozen drill the head off.Once the manifold is off you can apply heat and penetrating fluid.Weld a nut or use vice-grips to remove remaining bolt.

If I decide to do this do I install the gaskets dry with no sealant of any kind????

2. When re installing the 9 bolts do I put a dab of grease on them to make it easier to go back in and so they don't seize up?????