I don't own either. I have had the TH .75 on order with Tower for about a month with an expected delivery of end of October. Now their website no longer specifies an expected ship date which leads me to believe they are not getting straight answers from their supplier or having other issues. My options are to wait for the TH, or cancel that order and get the ASP.

The .91 four-stroke is the smallest four-stroke that is recommended for the Big Stik by GP, hence my question. I wanted to ensure it doesn't end up being under-powered with the .91.