Had exactly the same thing on mine. Replaced the starter clutch last year and hasn't happened again.

 

battery may be weak. Cells are withering I had this same issue this year with my powervision being connected on while the bike was hot. Extremely hard to even turn it over. My battery couldn’t take the load of both so I just disconnect my powervision and it starts fine.

 

A couple of questions. How old is your battery? Did you set your idle lower than 950-1050 rpm? And the comments about the starter clutch seem pretty solid. A warm/hot engine will need a few revolutions for the ECM and sensors to adjust for the hot engine, hold the starter switch for a couple of revolutions.

 

I've been through this myself with my 2010 Ultra Classic. That grinding sound is the starter clutch failing. As others have said replacing it will do away with that part of the issue. The deal with the 96 motors is they had weak compensator sprockets which would wear out the starter clutch when they got weak. The reason you do not have problems when cold is the parts in question have cold thick oil on them which doesn't slip as easy as hot oil does.

When you shut the bike off do you hear a clunk from the primary? If so you will also need to replace your compensator sprocket. When I replaced mine I found out Harley is on their fourth revision of that part to try to solve the problem. The 96 motors DO NOT need ACRs. Compression is not the issue, the flimsy compensator sprocket is the cause of all of this usually.

If you do not hear a clunk when you shut the motor off you might just need to replace your starter clutch. I replaced mine with an All ***** unit that was easy to install and only cost about $100. I will say that a lot of us have battled this issue over the years and to get things right we usually have to replace both parts. Once I did the bike starts perfect whether cold or hot with no strange noises.

Here is a link that shows the starter clutch or drive as it is sometimes called:
All ***** Starter Drive Clutch #79-2104 Harley Davidson

Here is the link I used in replacing mine:
Starter Clutch Replacement

I believe post number 7 is where I got my information from. The guy has step by step instructions with pictures. He is right about the steel ball being included in the new part. I lost the original during disassembly but didn't have to worry about it because the new drive had the ball already inserted and held in place with grease. After I replaced the drive the grinding noise went away but I could tell during hot starts that things still weren't right because the compensator sprocket was slipping and causing kickback on the starter.

Good luck with your repair. This issue is aggravating but is definitely not a battery or engine issue, so it shouldn't break the bank so to speak.

 

It's sad so many people are sold the cool-aid fix for a starter, starter parts, and even the compensator and all it is is a battery. Weak batteries cause the solenoid electrical magnet to be so weak, spring kicks starter drive out. And it's impossible for the compensator to slip. If the compensator was weak enough to affect starter, it would bang everytime you let clutch out a little fast or dropped off throttle hard.

 

Fought similar for years. Mine was 88 bored to 95 stock compression. I retarded the timing below 500 rpms, that seemed to help some. Battery passed load check. Replaced battery cables with #4. My o6 was before the weak compensator.

id suggest load check the battery, check both battery cables very good or just replace, the bike is 13 years old. Id suggest the starter drive gear aft that.

 

No cool aid fix. When mine acted up the first thing tested was the battery. Load tested and passed. Next was battery cables and grounds. Followed that with removing the primary cover and watching the starter gear while cranking the engine over.
the starter shaft quit turning, did not kick back and disengage from the gear. Starter clutch was the ONLY fault.

 

As I mentioned he may not have a weak compensator, but a LOT of us have found it to be faulty with this situation. When I replaced my starter drive I could still hear the clunk in the primary when I shut the bike off. This was because the circular springs in the compensator sprocket had gotten weak. I would literally turn it by hand when I took the primary cover off. I could see the wear polish on the contact points of the compensator when it was removed and disassembled.

As you stated lots of folks told me the battery was the culprit but it was not. Most of us here do not claim to know exactly what is wrong with a poster's bike. We just offer experience and knowledge we have gained in case it may help. If the OP is smart he or she will investigate using information from many posts instead of just assuming that someone speaking in an authoritarian manner has magically diagnosed the problem.

 

Thanks for all the help guys really appreciate it!

The battery is less than a year old, so I don't think its a battery issue. From the comments on this tread so far it sounds like the starter clutch might be the problem. I've ordered an All ***** starter clutch, will share the results once I replace it. If that doesn't fix it compensator is next.

 

Sounds to me like the starter don't have enough oomph and as a result the starter clutch is dying. It don't sound like bad comp. Bad comps clunk not grind. Battery may be weak even tho new but you need to go through all the cables and possibly disassemble / clean the starter solenoid. Make sure all starter cables are good. any corrosion, replace. If the terminals are simply crimped on the wires, solder them.. If the Fluke you got has peak voltage recording, you can connect across the cable and start the bike. It peak voltage drop is more than say 0.2 volts, the cable is the issue.