Left cylinder stops firing after engine is warmed up.
Posted: Tue May 16, 2017 4:09 pm
So this problem started last fall after my bike had set for a while. At first if I rode it with the RPMs up I could get the left cylinder to come back to life. I took an extended ride for about an hour and slowly the left cylinder began to work again. This then degraded into the left cylinder intermittently not working. The odd thing is that it fires just fine on both cylinders until it is warmed up. It has degenerated to the point where it now will run fine on both cylinders until warmed up then the left cylinder is dead. It afterfires and back fires which assume is gasoline being pumped thru the left cylinder igniting when it shouldn't be. I was planning to tackle this over the winter but I just never had the time. I had initially assumed it was carbs from sitting but now am leaning toward an electrical issue. It could really be a multitude of things. I'll start with electrical since that's the easiest to check. It could also be a valve problem or an issue with the timing chain where the timing is off just enough that the left cylinder won't fire. Or maybe it could be the carbs after all... If anyone has experienced a cylinder not firing after the engine is warm and solved the problem, please let me know. I'm somewhat perplexed by this.