Compression on 1962 Johnson FD-16

[OkieFromMuskogee]

Does anyone know what the compression should be on each cylinder on my 1962 Johnson 2-stroke FD-16? I got a reading of 50 psi on the bottom cylinder and 55 on the top. I'm assuming it should be around 100 psi on each. If compression is low on both, should I be thinking rings, cracked head, or blown head gasket? Thanks.

 

[Triumph55]

Does it run? Could be your gauge. Pull the head and take a look.

 

[racerone]

I have taken motors apart / done inspection on 62 models like yours.-----Found some to be just like new ( 24:1 mix does that ) and found some to be worn out junk.----Some of these motors were hardly used over their lifetime !!!----Remove the bypass covers and do the inspection !

 

[OkieFromMuskogee]

After much pulling, I finally got it started a week ago and took it to the lake. After running it at full throttle for about 30 minutes, I went back to the dock and when I slowed the throttle, it sounded like one of the cylinders stopped working and bogged out. Couldn't get it started after that.

 

[racerone]

If the ignition coils are original they need to be replaced !-----Does spark jump a gap of 1/4" or better, yes or no ??-----There may be a plate on top of the flywheel that allows you to inspect the coils.---Post picture of the coils looking through that hole.

 

[BlackoutBill21]

I had a motor with 60psi each cylinder. Ran great and started 2nd pull everytime!