Do a google search for "Mark Landoll's harmonic dampener". A number 
of LNC2 owners, including myself, use Mark's harmonic dampener. The 
dampener adds 12 pounds of weight to the propeller ring gear. It also 
helped my center of gravity.

Steve & Lorn,

 

Yep.

 

Consider reading this:

 

 

Especially the part that deals with:

 

"...The waveform in Figure 2 the instantaneous torque curve for an even-firing 4-cylinder engine, measured at the output flange of the crankshaft. ..."