>I did not lose any coolant, but it was >pinging at partial throttle. This is my primary concern. The bike was >previously owned by an older gentleman who I assume did not ride it very hard. >What about baseline jetting for this bike? Any ideas? Your knowledge and >help are greatly appreciated! > >Doug. Sounds like jetting may be close, but too lean in the bottom/middle. First use 100:1. The bike will run a small bit richer as more fuel will be available as less fuel is displaced by oil. Then is not fixed, raise the needle one or two notches (put the clip one or two lower on the needle). If a fully raised needle does not cure the problem, then go one size up on the pilot (low-speed) jet and fiddle with the needle to get it right. Usually no one changes the nozzle, so what you'll have is the factory jetting on the nozzle, which is usually close enough. Main jets usually are too rich from the factory, and since your problem is not blubbering at max throttle, leave that one alone for now. One other thing to consider is your riding style. Some riders follow RPM with throttle. These guys like to rev the bike or simply are soft on using the throttle. As a consequence, the needle is low in the body and less fuel is available at when backing off the slide, creating lean situations. Othe riders push the motor with the throttle, using big gulps of throttle in higher gears. Jordi Tarres, for example. His motors always sound like 300cc affairs as he really pushes the throttle and does not rev as much. In that style, you will have less tendency to ping when backing off the throttle, but your bike may run too lean during quick throttle openings. If your motor is jetted properly, a small change in throttle style can almost create the necessary difference in jetting. The same does not apply if your jetting is off too much. A great test for a generally lean situation is to place your hands over the throttle grip when the engine is idling with the palms pointing in opposite directions. Then quickly slide your hands off, whipping the slide immediately full open. If the motor bogs instead of revs quickly, you don't have enough fuel to supply the immediate demand. Your jetting is thus generally too lean on the bottom to mid, and the above fix may apply. Hope all this mess helps. Oh, and the thing about an older gentleman owning the bike confirms what I thought about oil fouling of the exhaust, especially given the rich oil mixture. Chris (CJ) Johnson Director of Engineering, College Park Industries, Inc. http://www.college-park.com (810) 294-7950 (at CPI), (616) 664-4173 (home office) papazit "at" juno.com |