I have a Craftsman T210 with the Kohler 5400 series engine (PS-KS540-3011) 18HP 541CC. It belongs to my cousin and their original issue is that it would not turn over. First, I found that current battery had only 1v, was told they replaced the battery, and it was a new one but could've not had a charge when bought. The battery that was on the mower had somewhere around 200cc.I used a battery off my zero turn (345cc) and the mower would turn over but very slowly but then stop at the compression stroke. After looking at YouTube`, I found that it could possibly be a bad ACR. A video showed that to bypass this issue, just cover the air intake while starting mower and it would start. I tried this and sure enough it worked. So I go ahead and tear engine apart, come to find that ACR is still okay. Its not damaged or seized up. Internals looked good for the most part. Talked with my cousin and her husband was the last person to use the mower. He told me that he went to start it one day and it would not turn over. He states that he got a new battery and it just wouldn't start. He says he kept trying to start it but eventually started to see fumes come out from underneath hood. He states after that happened, he tried again but nothing happened. I did adjust the valves several times but still no new results. I bench tested starter with a jump box and it seems to turn just fine. Im honestly stumped. Could it be the starter solenoid giving out? It has to be something electrical at this point.