Well, the bendix will surely kick out if there is some sort of ignition/timing issue….But, you are doing a compression test, so I am assuming there is no power to any of the plugs, correct?
Try doing the compression test with the other three plugs installed….

Some here might wonder why we’re discussing a looper in an antique forum. Many considered the loopers to be one of the final nails in OMC’s coffin; so they do have some historical significance.

The early 90 degree loopers were often referred to as “bloopers”. But, these engines got to be pretty nice after the 93 block improvements and the addition of adjustable low speed fuel needles a few years later.
The 60 degree loopers were amazing engines that were under rated in their first production year. The ignition system is pretty strange, and prone to RFI interference, especially if the wrong plugs were used. Early 60 degree V6s had some block casting flaws that caused water to leak into the number one cylinder, I would say that most of the affected powerheads were replaced either for free or a greatly reduced price. The early 60 degree V4s had some base gasket/megaphone issues that caused water leakage into the lower cylinders….But, like the V6s, most of the affected powerheads/megaphones were replaced.
A big nail in the OMC coffin occured when we foolishly bought up all those boat companies. Limiting the OMC boat companies to OMC engines/outdrives restricted their sales. OMC lost control of their engines letting the boat companies stock pile (wreck them) in their warehouses. Poor rigging, use on non OEM wiring/controls/cables/props made us look like complete idiots also. All this boat packaging crap killed the dealer network as well.
I guess that the premature introduction of the ficht engines was the final nail in the coffin, many owners and dealers were left “holding the bag” when BRP took over and only honored warranties on 2000 and newer engines. But, I surely can’t blame BRP for not wanting to take on the liabilities for those early engines.