Bonneville America Forums Forums Technical Forums General Tech Only running on one cylander

When my cdi went bad I would intermittently lose my left cylander. Switched coils and plug wires around and still would only lose the left cylander. After 3 weeks off messing with it I bit the bullet and bought a Pro Com, set it to the number that matched the stock unit, installed it and haven't had any trouble since. My bike has always seemed to be cold blooded so it doesn't seem to take any longer to warm up than before. I have seen that some speculate that the Pro Com likes a higher voltage, I'm not totally sold on that. I have another theory, I think that it likes a higher idle. After reading a thread over in the performance section on the efi bikes needing a higher idle I started paying more attention to mine even though it is a carb model. If I set my idle below roughly 1150 rpms I noticed that my neutral light flickers, set it at 1150 and its solid. I think that the stock maps from Pro Com may be set to run at a slightly higher idle than the stock unit. Some guys have said that with using the custom map options they have been able to eliminate the cold starts. This makes sense if the custom map also lowers the idle. It seems to me that a lot of people suffer from "Harley Idle Syndrome" as in they set their idle low because it sounds cool. I bet if those of us with the Pro Coms set our idles slightly higher, like around 1150 which the efi models seem to like, or altered the idle in the map the Pro Com issue may be resolved. I think that using a low idle with a stock Pro Com map may unknowingly be responsible for the cold starts. It is just a theory, I may or may not be right, after all I am not a motorcycle mechanic I'm just forced to play one in real life!lol