I have searched around for answers, but I thought I would make a post to get advice. I have a 2010 Fatboy. It has S.E. Heavy Breather, V.H. pipes, and V.H. Fuel Pak LED as the only engine mods. The first start of the day is perfect. However, after it warms up, sometimes it gets hard to start. It doesnt fo it all the time, but sometimes it will turn over 3 or 4 times, then make a grinding noise. Sometimes after that grinding noise it will puff some smoke out the breather. Sometimes the grind is quick and keeps turning over until it starts. I've recently replaced plugs and wires. The battery was bought earlier this year. Could it be starter, starter clutch, starter relay, something else? I've emailed Vance and Hines with bike info and they sent me the codes to put into the fuel pak. That didn't seem to help.
Any advice is appreciated. Thanks! I have a video I will try to get on here.

 

How old is the battery?

 

I forgot to add that, I bought it earlier this year

 

Had a similar problem with wife car, start fine when cold but hard to start when warm. No choke on fi, turned out temp sensor was bad, thought the engine was cold and increased the fuel. Did not bring in a code and indy could not find it, dealer was stumped too. Replaced temp sensor and problem gone. I would also unhook your fuel processor, my PC3 on previous bike made starting a little bit longer.

 

I gave a listen to the video , and it's hard for me to tell , but it sounds like the compensator knocking , possibly because of a weak starter . I would start by checking your cables ( including inside the jacket ) making sure there clean and tight , then go from there . The starter solenoid and starter clutch is were I would look next . Check out this video , weak starters have been known to cause hot start issues .

https://www.bing.com/videos/search?q...6FORM%3DVDVVXX

 

I have a 2011 Fatboy 96CI with Vance and Hines pipes and a Dynojet Power Commander V and it was doing the same. I replaced battery but still had a rough warm start....removed the Dynojet Power Commander and it starts like a champ. Previously I was also getting some blowback out of the air filter as well. My belief is it is a timing issue that was not being correctly handled by the dynojet PCV and causing an incorrect firing time.

I'm no expert on the engine stuff...I just know removing the PCV made the problem disappear.

 

I've been thinking the Fuel Pak, too. I am taking some time off next. I plan to take the Fuel Pak off and see how that does.