Originally Posted by Goofeyfoot
Well, you can get it repaired. I guess you can use some sort of Epoxy called “marine tex” or something like that. I just wonder whether that is ever going to be something you can rely on or whether it is a Band-Aid?
Brazing is not an option because the dissimilarity of the metals.
How do people feel about the Epoxy solution?
Pete and Doug are right; the HE is supplied from the factory with a glued-in neck.
There is even a kit, shown below, to replace it. This is listed for an MD2040, but it may fit the 2010, 20 and 30 as well. Check with parts for engines to be sure.
As for the HE being a poor design, I'd rate the HE as adequate to reasonably good. There are of course certain procedures that need to be followed when fitting and maintaining it, but, unless you get one that is made from a metal that is as least as noble as cupro-nickel, an all-metal one will have similar idiosyncracies.
For the MD2020 exchanger, maintenance
is pretty easy, regularly scheduled cleaning
will have a big affect on it's operation and durability. Close attention should be paid when refitting after cleaning
; the sealing areas on the housing and the cooling
bundle should be clean, almost bright metal with no scaling, the bundle should be centered to allow maximum contact of all four sealing areas, the boots should be flexible with clean sealing areas (no hard stuck-on scaling should be present), and high quality hose clamps should be used.
The exhaust elbow
should also be checked to ensure that it's water
passages aren't clogged with scale, if they are, that can cause excess pressure in the raw water
side, which can lead to raw and fresh water
mixing, not a good thing, especially if you're running in saltwater.