Small Engines (Lawn Mowers, etc.): weak cranking, mtd yard machines, cold cranking amps

Question
i have a 2000 mtd yard machines w/a 16.5 h.p. briggs. having trouble getting full cranking power at the turn of the key. installed new battery, new solenoid. cleaned all connections with a dremel. put jumper cable from battery direct to the starter, still too slow to turn over enough to start. got good spark to the plug. can i test the starter another way, without spending $100 for a new one, or does this definitely soung like my problem? thanks.    p.s. i have the negative grounded on metal, but NOT on the frame? is this o.k. ?

Answer
Did you disconnect and clean the battery ground terminal where it connects to the frame?
There are some tests you can perform to check the battery cables if you have a volt meter.  There are also some tests for the starter but they require expensive an expensive DC shunt and a tachometer.

I have found bad battery cables.  Typically manufacture do not use the best cables.  They are sometimes borderline of being too small to handle the current.  It may be easier to replace the battery cables and is much cheaper than replacing the starter.
One final question, what battery is in the mower and what is the cold cranking amps, CCA?  Is there room for a bigger battery?
Let me know.
Eric