Re: 1974 Evinrude Yachtwin 4hp – failing to start

[Casey Lynn]

quote legendre:

First off, check compression – that’s just standard drill.

If you don’t have a tester, then pull the plugs, put your thumb firmly over one plug hole, and have someone pull the recoil once or twice. If the motor promptly blows your finger off the plug hole, then move to the other cylinder. If both blow your thumb off the hole, then you probably have enough compression to run it.

Not enough compression to blow your finger off? Then look for compression leaking issues in the power head.

Ahhh……so the proper way to check compression is with your thumb? And if your thumb tells you it is low you are advising disassembly and look for the loss of compression…………..(insert sound of crickets here)………!