jano mad racer these motors are great they are very inexpensive and run as good or better then most of the named motors out there i run the 5 port .21 and runs great in truggy and buggy and now have the 6 port .25 in truggy and a 3 port .21 race spec in the buggy and they are all good motors and get plenty of life out of them. my 5 port has alittle over 9 gallons on it now and finally low on compression where needs to be replaced. i know rb makes good motors and unfurtintly they are all over priced for the average racer like myself that wants to go fast but pay as little as possible. let us know if need anything else thnx will g