Here's my dilema, and my Harley dealership says there's nothing wrong...

I pull the bike out of my garage... starts right up no problem. I run it, ride it, park it, and if it sits out long enough ie. I go for a bite, I come back and it doesn't start the first or second time I try to light it up (unless the bike has been sitting long enough to cool down). It turns over just fine, battery seems strong, but it just doesn't start. This ONLY happens after I go for a ride and let it sit and then try to start it up again while it's still hot. After the second or third time trying to turn it over, it eventually fires up. If I shut it down, and try to start it up right away, there isn't an issue.

My first guess would be the starter, but I had it checked and it's fine. Second guess would be my coils (aftermarket dynatek coils) but the output is right where it needs to be (tested by Harley). My third guess would be the spark plugs. I've noticed some frequent carbon build-up on the tips of the spark plugs when I use dielectric grease. From what I can tell, when I wipe the carbon off, the bike starts up right away. This leads me to believe that the starting problem is caused by a poor "connection" from the wires to the plugs. I can't say for sure that this is the problem, but it's all I have to work with to figure out this nonsense starting problem.

1. If it is the carbon on the spark plug tips, what may be causing this and how can it be prevented?
2. What else should I be checking that Harley may overlook when they're inspecting the bike without riding it for an hour or so?

Note: Dynatek coils, 8mm spark plug wires, screaming eagle race tuner. Everything else related to starting is stock.

Please help!!!

 

Has your bike been set up on a dyno? Could be as simple as the fuelling is about OK when cold, but out when warm.

 

Based on your post, it sounds like the bike starts fine when the motor is hot or cold, just not when it's warm. I'm assuming that when you "go for a bite" you mean 30 or so minutes.

If that's the case, I check 2 things first.

Maybe the race tuner thinks that the motor is warm enough that it doesn't require any extra fuel for the restart, when in fact it does. My carbed bike, even on a warm day, will require partial choke to restart after a 30-45 minute break.

If you have your original coil, try reinstalling it. Coils often start failing when they get hot. Once you stop moving and heat rises off the motor heating the coil, it may not be creating a hot enough spark. It's a bit of a long shot, but easy to eliminate if you have the original coil.

 

Good points. Sounds to me like you guys are right about the super tuner. The dealer set it up so I'll have to ask them about getting proper fuel when the bike is warm vs. hot or cold. Is this something I should leave in the hands of my dealer or should I get the bike fully tweaked on the dyno and eliminate any doubt?

The dynatek coils are heavier duty then the stock coils, construction wise as well as performance. Plus they are mounted on the side of the motor and spaced off it with adequate breathing room. I'd imagine they wouldn't get any hotter then the stock coils would in the stock location, but if the dyno doesn't fix the problem I'm going to have to pull the dynatek and re-install the stock coils and see if it makes a difference.

Any advice on the dyno or should the operators know exactly how to set the bike up for optimal performance?

 

IMHO dyno is best. It should remove all doubt and ensure fuelling is just right through the whole rev range. If you have a stock set-up on your bike your experience suggests it isn't quite right at present. On the other hand if you are thinking of changing the exhaust soon, or fitting a new air filter do it before you have your bike dynoed!

 

I have already changed the pipes and air filter. Asides from cosmetics the bike is going to be using the setup I have until I get into some motor mods next year. Dyno it is!

 

Let us know how you get on.

 

Just got the bike back from the dyno. Coils tested fine, battery was dropping down below 10V however but the alternator is fine. Time to replace the battery. He's convinced that was the problem but did add 5% of fuel on start up and managed to squeak out 10 more horsepower and almost 10 more ft/lbs of torque! WOW what a difference. The motor is comfortable at 120 km/h in 4th and the throttle response is killer. Haven't had the bike back long enough to check if my starting problem was resolved but I'm going to throw in a new battery and see how she responds.