From the first day I bought my S10 it turned over real slow and was a little hard to start. When the original YTZ12 battery played out, I put in a Yuasa YTZ14 battery. It turned over a little bit better with the 14, but still strained to start. I ran the 14 for a couple on months and decided to put in a WPS Featherweight Lithium battery. The Lithium battery has been in for two years and it turns the motor over much better and the S10 starts instantly. I couldn't be happier.