Posted by Frank on August 10, 1999 at 19:16:16:
In Reply to: Backfiring and flame´s posted by Hans on August 09, 1999 at 22:49:16:
Hans, My bike does the same thing after a long ride. I shut the engine off and if it is dark outside you can actually see a blue flash blow out of the pipe and backfire once. The cause is unburnt fuel/gas slips out of the exhaust valves when you shut the bike off. The pipe is so hot that it exhnites the gas in the pipe. I have heard that this can burn your valves, but I have over 36k on my bike and it has been doing it ever since I put an aftermarket pipe on. It even occurred with the stock muffler but it was more muffled. It's not as bad now that I have richened up the mixture by removing the spacer in the carb and rejetting but still occurs, especially on hot days. I wouldn't worry about it as long as the bike is running ok. You may need a valved adjustment. good luck. ride safe.