Bertram 20 Moppie Repowered with Yanmar Diesel - 07/02/2008
Untitled Page Mack Boring, the New Jersey distributor for Yanmar recently repowered a vintage Bertram 20, better known as the Moppie. Originally it was powered by a 175-hp OMC gas engine with sterndrive. Boring replaced the 746-lb. gas sterndrive package with a 683-lb. 6BY220Z diesel driving through a MerCruiser Bravo III. Mack Boring sent us his test results recently and the results were so startling that we asked to test the boat ourselves. In the meantime, we’re so excited by the tremendous improvement in fuel efficiency obtained by the Yanmar 220-hp diesel that we are passing them along.

Yanmar 6BY
A vintage Bertram Moppie after being repowered with a Yanmar diesel goes
10 mph faster and gets over 118% more mpg.

Yanmar 6BY
Mack’s Moppie being wrung out along the New Jersey coast this spring.

Moppie Performance
Testing was done by Mack Boring’s staff.

Moppie Specs

Mack's Moppie
Note how the rehab makes this very old boat look like new.

The diesel engine actually takes up less space that the old gas engine.