My 07 Road King 96” has a “hot start” problem. The starter kicks out/back and screeches when the motor is at normal operating temperatures but never on cold starts. I cringe and avoid “hot starts” whenever possible. When on a long ride yesterday I brought along spark plug wrench. After about an hour of riding I simply pulled the plug wires and loosened both plugs several turns to release the compression. I retightened them and tried the starter…..No screech or kick out! Down the road I repeated the test a couple more times with the same results. I’ve concluded it’s the compression when the motor is at normal operating temperatures that is causing the starting issue and not the compensator or starter. I wonder how many compensators have been replaced needlessly?
I thinking having compression releases installed is the best solution but I’m still considering other options. Any thoughts?

 

I wonder if this is what is going on with my bike.?

When warm, if I stall it, or shut it off it WILL NOT start within the first 2-ish minutes, no matter what I do, though it cranks fine.

Ive never tried this cold...only when bike is hot ( I think)

Ill have to run a test.

Drivetrain 100% stock

2004 rkc 88 tc

 

 

My '07 dyna had the same problem at around 55,000 miles. It was the starter clutch. No problems for the next 35,000 so far since I changed it.

 

Compression is often higher with a hot engine vs cold. This is partly due to the fact that ring seal is better when the engine is hot. Also a hot engine will heat up the intake air expanding it. That increases the compression as well. Just these two things are enough for a kick back on some bikes. One solution is compression releases. Another is S&S Easy start cams. And then there's possibly a tuning solution to retard the spark. But before you spend money check to make sure you don't have a large carbon build up in the cylinders with an endoscope.

 

Compensator or clutch starter; my money is on the compensator. They were really junk until 2011 when they were just junk.

 

Another contributor to hot start problems is a battery that is on it's way out.

 

Id look at the compensator and the starter Real hard before going at compression releases

WP

 

Your '07 never had this problem before, right? It's hard to imagine the compression improved over the years, although now that I type it I suppose you could have a carbon build up. However..... wherever the motor is stopped you'd think at least one valve would be open on at least one cylinder if not both. I wonder if the time spent pulling spark plugs isn't enough time for your problem to clear. Could be temperature related wrt the starter motor, could be a starter solenoid as per the post above. Compensator? Never had problems with mine, maybe engine temperature has an effect?
I would try a starter solenoid and then a start motor long before I pulled the heads to get compression releases installed. Another good thing already mentioned would be a battery load check and thorough cleaning of both ends of both battery cables. Weak battery or loose connections could have your starter solenoid 'bouncing back' when your engine is warm? Good luck getting it sorted.

 

I will tell you from experience that it is a compensator issue. Upgrade the comp and make sure your battery is good and you can forget about compression releases. This may be the most discussed topic around, that and what kind of oil to use...