merc riser gaskets-to seal or not to seal-

[MATMAN29]

Any body know the down sides to using gasket sealer on the shiny riser gaskets.I have read the service bulletin that says not to use it so when I put new manifolds & risers on I didnt and they leaked.I talked to my local merc mech and he said they do use sealer on them (the brown stuff) Every body has a different opinion on it but since I went with out and they leaked ime going to use it this time.Any thoughts on this issue? its a 99 4.3 merc

 

[rodbolt]

Re: merc riser gaskets-to seal or not to seal-

what method did you use to check for surface flatness on the risers and manifolds? the max allowable is .004". were both riser and manifold new or used ?<br /> if you must run sealant use the paper gaskets from napa.

 

[Don S]

Re: merc riser gaskets-to seal or not to seal-

NO SEALANT. Just like the Mercruiser manual and the service bulletin below says.<br /><br /> http://www.boatfix.com/merc/Bullet/99/99_10.pdf