KE4 / Mark 7 are what we would now call modular design motors, that is, they are built up from several distinct components. Good in that individual components can be accessed and changed it need be and bad in that care must be taken when assembling to make sure all gaskets are in place and will seal joints to prevent leakage. You find out if you have done it right when you start it up engine. Either leaks or it doesn’t. Fortunately until the gasket
sealant sets up engine can be disassembled and situation corrected. Usually without damaging gaskets so they can be reused. Electric hair dryer on high may help soften
not yet set up sealant to save gaskets.
Corrosion of the aluminum/zinc alloy water jackets is normally not a problem with motors
operated in fresh water. Salt or polluted water especially if left on boat will chew up the
jackets. Propeller and lower unit will reflect this also. A corroded and pitted propeller
likely means similar condition with water jackets. JB Weld can be used to repair pitted
interior of water jackets if not excessive.
If the cast iron cylinders are heavily corroded they can be removed and bead blasted to
bright metal and reused. When installing cylinder on pistons be sure ends of all three rings
center on the locating pin on piston….you have to get that right…if engine turns over tight
it could be ring is riding on locating pin…take it apart and start over. Note how motor
turns over before working on it so you will have a reference "feel" for how it should be after reassembly.
If you intend to do a complete tear down remove rings from pistons before removing piston
pin…failure to do so can lead to damage to piston and rings…this is a "do it right or do not
do it." The Kiekhaefer KE4 & Mark 7 were well proven designs with a gearfoot strong enough to be used with larger and more powerful KE7, KF7,KG7 and KG4. Condition of a KE4
Mark 7 will reflect prior use and care. An original untouched powerhead and gear foot will have the same seals and bearings it left the factory with in late 1940s early 1950s. If you are
lucky there will be no serious wear or corrosion issues to crankshaft. driveshaft or propshaft
Sometimes there are and you will either have to live with what you find or find something
better…a parts motor is a good thing to have around.
Louis
I
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