Reply To: Sealant or not on old NOS fiber gaskets?

[Sam M.]

I have a few things to add on to what JACQUES said.

There are different kinds and different thicknesses of gasket material.  You want some that can resist fuel, oil and water.  There is a blue type that I was told is for radiators and won’t be suitable.  Common types are paper and cork, but there is also a rubber type that can work too.  Paper type is most often used.  I find that not all paper types are created equal as the brand I currently have tends to make loose fuzzy pieces when I cut tight corners with it (which you do not want getting into the engine).  Seems to be an uncommon problem though.  Cork gasket material tends to only get used for certain things, like pressure tank gaskets.  (All of the motors in your list except for the Johnson 2.5hp and the McCullochs were designed to run on a remote pressure tank.)  For home-made cylinder heads, I’m pretty sure there is gasket material with a metal core that can work.

It’s good to have your new gasket material’s thickness close to the original’s thickness so parts fit properly.  I recall reading (probably in the AOMCI Current Projects section) that someone discovered the new powerhead base gasket they had tried to use was too thin because the driveshaft was pushing up on the crankshaft and putting excess pressure on the bearings.  You don’t want that.  Also, if your new thickness is really different, you may need to adjust your shift linkage to compensate, however as of now, I have not needed to adjust any shift linkage so I don’t know if it is that sensitive.

I agree that if a cork float’s coating is not peeling, there is no need to sand or refinish it.

There are 2 main types of spark plug wire.  The “solid” type of spark plug wire JACQUES mentionned on page 2 is the copper type.  The other type (without copper) is for electronic ignition.  You want the copper-core wire for your points and condensor ignition systems.