hard pull

[stepheneff]

Got a 76 merc 20hp not running. Found the ignition wiring burned up so I replaced the electronic switch module and repaired the trigger. Now I had spark on both plugs. Figured that was the problem, so I put things back together. With spark plugs out the motor turns easily. When I put in the plugs I can barely pull the starter rope. Can get it to turn but very hard. What is going on?

 

[Faztbullet]

I got its brother in shed..runs excellent but take a BIG man to rip the starter recoil. The duck hunters keep bringing it back,....I have sold/refunded it 6 times. Compression 130PSI per cylinder.

 

[stepheneff]

I don't think I am strong enough to start this. This can't be normal. Could there be a compression relief for easier start that isn't working?