Mk20 powerhead on KG-7 Tower.

[rickinfarmington]

Is it feasible to mount a Mark 20 power head on a KG-7 fishing tower? What would be the driveshaft length?

Rick

[foot_doctor]

Everything below the powerhead will fit correctly. The driveshaft will engage the crank. as it should. No adjustments necessary. Have fun with it! R.T.

[foot_doctor]

Whoops, I forgot about the bottom bearing caps being different. Use the cap from a KG7 style engine on your MK20. It will keep the pivot pin in it’s place, and prevent exhaust gas from escaping beneith the carb. Use the KG7 powerhead to tower housing gasket. R.T.

[dave-bernard]

no need to remove the cap just the plate. to mount the tank you need to change the rear water jacket cover and install the front mounting bracket. also set up the spark advance handle unless you use a dead man throttle.

[rickinfarmington]

thanks guys, this will be a fun engine to run on my Hal Kelly Airborne.

RickinMaine

[20mercman]

The bolt pattern for the front tank mount plate for the KH-7 & earlier motors is a bit different than the Mark 20. You will need to modify or make a new front tank bracket. As for the front of the drive shaft housing, as the other’s have noted, the lower bearing carrier is different. 1954 and earlier Mk-20’s used a water cooled lower bearing carrier that was two pieces. The carrier and the lower plate. Later production Mark 20’s used a one piece lower bearing carrier in the same style as the Mark 25. If you have the two piece plate, then you can do as Dave suggested and just use the lower plate from the KH/KG/KF/KE style motors to seal up the drive shaft housing and prevent the swivel pin from working it’s way up.

On a project my son and I are building, we are using an enhanced Mk-25 powerhead on the KF-7 lower unit. This lower bearing carrier is different, and I had to make a block off plate for the front of the drive shaft housing. Easy to do.

Have fun with your project!!!!!!

Steve

[dave-bernard]

or a thin adapter plate to cover the pin. 1/8 in should do it.

[outboard315]

The typical rat rod motor is a KE7 tower and KF/G7 lowerunit and your choice of Mark 20, 25, 28, Merc 200, 250 or other powerhead.

On the Mark 20 and 25 I believe you can change the lower bearing holder to the earlier style with the pin cover. Or drill and tap the tower for a cover plate, similar to the 20H.

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