They are widely available and inexpensive in the UK but I have no idea who provides spares support for them in your country, sorry. I have a 46 and a 53. They are nice reliable engines but not as powerful as some others.
They are basically the same engine as ASP. Those you can get from Just Engines
http://www.justengines.unseen.org/ASP.htm and Paul keeps spares for all the engines he sells.
Steve