Tuning The Outfit: The fine points of racing! |
| There are several fine points to tuning the
entire outfit for optimum performance. Listed below are a
few points that can have a significant effect on 'UJ'
class outfits: Try various engine angles and heights to find the best setup for your particular boat. Some weather and water conditions require a different setup. For example, in windy and rough conditions you may want to trim the engine under a bit further, to keep the nose of the boat down. The type and mix of fuel is critical for 'J' engines. First, use a high grade oil. Try a few different ones and look for clean plugs, and good engine response. I have found that Yamalube, Red Line, Quaker State oil work very well. However, there are many good oils available. Next use a low octane gasoline. These engines have relatively low compression ratios, and don't need high octane fuel. Finally, the fuel ratio should be about 12:1 to 15:1. This sounds very rich with oil, and you will need to use a .057 or .058 jet with this mix, but you will find better engine performance. Again, testing the ratio and jet with each engine is very important for consistent success. Tuning the engine on a test wheel at the race site. This is important since elevation and weather conditions vary dramatically. Use the same test wheel every time you test your engine and write down the results. The best test wheel for the 'J' will allow it to run at 6500 to 6800 RPMs. Run the engine at wide open throttle, and hold it there for 30 to 40 seconds and monitor the RPMs on a tachometer. If the engine slows down, the low speed adjustment is set too lean. Open this adjustment up at least 1/2 to 1 turn and test the engine again. |