Our Services Manufacturer and supplier of perfomance exhaust systems for racing Go-Karts. Engine Repairs and Dyno Tuning Go kart and accessory sales Stockists of Arrow Karts and Kartec products Farm Bike ATV Mufflers (product list for available models) Powermac also have an Excavation business with 38 years expertise in under road boring Directional Drilling and pipe laying.  http://johnstonecourt.com/index.php?pr=Partners Click to view