06 hard starting
 

as soon as you turn on the ignition, hit start......dont wait.....worth a try.......works on my 07.......wait too long and I get what you get.

Sounds like the usual Comp sprocket failure. Should be very obvious when you tear it down. If the bike has the original factory "auto adjust" chain tensioner you might consider upgrading to the Hayden Spring loaded tensioner or similar as this seems to be the root of all the problems.

Related, but kind of not, I had the same exact issue on a 2000 Chevy S-10. Turns out one of the injectors would leak after shutdown while hot making restarts difficult since it would foul the plug. Injector cleaner would only help for a very short time, and then eventually not help at all.

Changed injectors, fixed the issue. Try pulling a plug immediately when you're having this issue to see if it's wet.

Also, your crank position sensor could be the reason as well. It has a tendency to make the bike throw sparks at weird locations, which could cause your random noises and grey smoke at startup (depending on when the spark fires on the intake stroke).

I believe that was 07, so I'm clear of that.

Mine does the same thing, not every time but at random but the symptoms are exactly the same. Never happens cold, only when hot and if i stop for gas ect. Ive tried hitting start as soon as i turn on the ignition and it doesnt help mine. I was thinking of getting a new battery, ive heard that could also be the culprit. For me though its not a big enough problem (yet) where its bugged me enough to get to the bottom of it. I know this happens to alot of bikes so i figured it was no big deal. Going to watch this thread and see what happens.

Strange that the problem manifests itself when hot and not cold so you have to look at what changes when the bike is hot. Straight off the bat we know that the ECU configuration is different on a hot/warm start. That doesn't mean the ECU has failed but we may be looking at a sensor fault. Starting with the least reliable component the Crank Position Sensor may be failing. This will only generate a DTC when the bike is cranking for more than 6 seconds and the motor doesn't start. From memory I think the codes are P0374 P0373 but like I say the bike has to crank for 6 seconds before a fault situation exists. On a bike with that kind of miles on it I would change the CKP anyway. Also worth considering are the inlet manifold seals which could be leaking when everything heats up and expands. These are easy to check. Clearly there is a list as long as your arm of things that could cause this fault on an EFi bike but it makes sense to look at the most common Harley faults first.

cranking fuel map ....
 

You might also check the crank/warm up map ...what you are describing sounds lot like it's too rich during cranking....and maybe the timing could be retarded 1-2 degree's at start up ...
when the motor is cold it needs the extra fuel ...but when it's hot ...that make the mixture too rich ..and with the timing too advance ...cause's the kick back and the grey smoke out the intake ...
take a few points out at the higher temps., and retard the starting timing ....(in the 80-100 map section 750-1250 rpm range) a couple degrees and then retest ,,,,
hope this helps ...good luck !!

https://cimg2.ibsrv.net/gimg/www.hdf...ace3b0a00b.jpg
https://cimg2.ibsrv.net/gimg/www.hdf...c7c8ba09da.jpg

Oh yeah, i forgot to mention it did happen almost every time it got hot before i bought the FP3 fuelpak and flashed my bike. It made my idle go down and my bike run better, now that situation only happens once in a great while. Sure seemed to help which would support the last posters reply.