Amperage is the same from start to finish in an electrical system, so all power cables could have issues along with the contacts in your starter solenoid.
Another thing, an ohm test may not tell you everything. Say if you have 100 strands in a cable and 99 of them are broken and 1 makes perfect contact from one terminal to the other, you will have 0 ohms (no resistance), but you will not be able to start the ski and that one strand will surely burn up if you try to draw too much through it. Something similar can cause slow cranking if you have 20 of those 100 strands in contact, it will be a bottle neck and not allow enough amperage to pass to crank the engine fast enough.
First, test battery voltage from B+ to B- and make a note. Then test "solenoid in" to B- and compare to the battery voltage. Next test B+ to the ground wire on the starter and compare to battery voltage. Each of these should be less than .1v of battery voltage.
The best way to test a wire is going to be a voltage drop. You would put one end of your volt meter on your battery and the other on your starter positive terminal and crank it, but don't start it. Since you are testing the positive side of your starting system, your voltage should read less than .5v. If it's too high, you will need to test each wire the same way. B+ to solenoid in, solenoid in to solenoid out, solenoid out to starter +. Each one should be less than .2v, but 0v is ideal.
Then test your ground the same way. Put one meter lead on B- and the other end on your starter ground wire and crank it again. This should read under .2v as well. You can test a bare spot on your engine as well the same way to make sure your ground wire is acutally grounding your engine.
In the sample above, if you have 20 out of 100 strands making contact, it would show up as good on an ohm meter but if the draw was high enough, you'd end up with a large voltage drop.
