I have a used Rotunda Super Star II tester for sale. I have had it a while. Used it for reading service codes on my 98 Nautique with the GT-40 engine controlled by the EEC-IV computer. This tester along with the diagnostic manual will help diagnose sensor/actuator problems. It has saved me a fortune by not replacing parts that were not bad. It has seen a lot of wear, battery door is taped on, and there is some tape on the cord but it works perfectly and comes with a copy of the original manual and the original hard case. I want $150.00 + $10.00 to ship it anywhere in the U.S.