Re: Unburned fuel

[wiscoboater]

You might try going up 1 heat range in plug and making sure your points, coils and plug wires are in top shape. Another thing to try is FrankR’s timing tools to be sure your spark timing is optimized. Franks tools are top notch and will really get you dialed in. With the hugely oil rich mixtures needed in the RD series of motors I do not think you will ever eliminate the "floating rainbow" completely. If it’s an environmental concern, look into some of the biodegradable 2 stroke oils offered.