I can rope start my Merc 150's as long as it is lined up on the backside of the compression stroke. Might be a case of a weak starter or a weak arm or a rusted crank, sticking rings. Take the plugs out spray some pb blaster in each hole and turn the flywheel by hand you should be able to decipher each bump of compression for each hole motr should turn easily. If the motor feels tight and binding doing this ..rut roh. If not I would revisit the weak starter and arm.
B
|