And my connections to the battery are perfectly clean also.

How about the ground strap from the frame to the engine?

If that's not it, it might be time to pull the starter and see what the brushes and commutator look like.

My 149 has a ground strap as Matt G. posted.

Lucky for me that my s/g system proves to be working A-1. I made doubble suer my ground connections are clean with grease smeared over the batt. terms. I have a Husky 300cca. and had no problem starting up in the 19-25 deg. weather the past week. It starts at about 3-4 turns of the grank. I keep the choke and throttle cable sprayed with wd-40 to the rescue. Did have that freeze up a little. Make sure the batt. is charged fully and try again.:beerchug:

Today I started my 782 with its 230cca and it started fine that 340cca should turn it over fairly easily.

First year my son acquired his 1650 It was hard to start all the time, tried starting with a car battery same thing, checked valve settings and new points still hard to start, finally pulled starter out started to disassemble, cracked and broken pieces started falling out everywhere that were burnt looking, bought new starter installed it, never new they were supposed to start that easy.

My 1450 always cranked slow in the winter temps and tough to start. I changed all the cables to 4 gauge wire and never had an issue again. I did not see in the post if your cables were still factory or not.

Ground wire from the engine to frame connection is good also. I do have all original wires. The engine seemed to crank pretty slow even in the summer time, but always started. So I guess my next move is to replace all the battery cables?

woh
 

I just started my 127 and 105, they both have new battries that are fully charged. They are out in my shed and its cold, they took a few tries to get them fired......Kinda slow cranking but finally fired over. I might try and get some better battery cables for them and put an additional ground wire. My grounds are all clean and have new wire harness too on both of them. Once they are running and get a little warm they fire right up..........

this may sound stupid but it worked for me. I had the same problem with it not wanting to turn over. Old man down the road said to get a 250w heat lamp and put it near the oil pan and let it heat. 4 and a half hours later the engine was turning over like it was in the middle of July. Worked great, give it a try.