Just picked up an 07 Classic and only have 300 mi. on it it so far.Everything is great with the exception that over the past two days when I go to start her and push the starter button there is what sounds like a small detonation or backfire. A couple of times the engine hasn't started on the first starter button push and when you push it a second time ithe engine turns over several times then catches and starts up. I have a service appointment later this week to get it checked out but was wondering if anyone had similiar experiences or thoughts on what the cause might be. Any info would be appreciated so I can discuss it in a little more depth with the service guys at the dealership
Thanks

 

maybe you have some bad gas. Put some good premium gas in your tank and get rid of whatever you have in there now.

 

Make sure you give the fuel injection time to energise. You can hear it spin-up when you press the engine run switch, then hit the start button.

 

Starter Clunk?

TT258 – August 9, 2006

Primary Drive / Starter Noise Complaints

Several dealers and customers have commented about a “clunking” noise coming from the
primary housing during start up. Most dealers suspect a loose compensator because the
noise seems to come from the front of the housing. Customers tend to associate it with a
starter issue like improper starter drive engagement into the clutch’s ring gear. In fact the
condition they are noticing is what is referred to as “Starter Knock”. This is a normal sound
and condition for all 2007 Twin Cam models.

Changes in the primary drive system increased the diameter and inertial effects of the
rotating components (clutch and sprocket assembly, ring gear, and engine sprocket). Also,
the engine control system is calibrated to start the engine as quickly as possible (short crank
to run times) and to run up to the predetermined engine idle speed as quickly as possible to
provide very positive starting.

Because the engine fires and then runs up to speed very quickly, there is a large torque input
and instantaneous speed differential between the engine and spring loaded compensator
mounted between the engine and the driveline. The compensator is there to dampen the high
torque spikes inherent in a large displacement V-Twin.
Because of the increased inertia in the rotating components in the driveline, their rotational
speed cannot increase as fast as the engine, so the springs in the compensator momentarily
bottom and results in the sound that you hear.
The same sound exists in the 2006 Dyna models, but to a lesser extent. The increase in
displacement to 1584cc increased the torque spike and speed differential in the 2007’s and
causes the sound to be more noticeable.
There is no damage associated with the compensator bottoming.
Identifying characteristics of this condition:
1. It may be intermittent, as it is dependant on the start up conditions and how quickly the
ignition and engine RPM occurs.
2. It will be a single event. Once the starter is disengaged or the compensator is loaded
the sound will stop, unlike a loose sprocket assembly.
3. The condition may be more noticeable on Touring models due to the shorter primary
drive (shaft center to center distance) and associated shorter chain run. The extra
body parts like fairings and saddlebags also tend to reflect powertrain sounds upward,
towards your ears.

 

I have and 07 and it does the same thing. I give it plenty of time, but sometimes it hesitates so bad for a split second I think the battery is not charged or the compression is too high ( nope ) . Dealer said no problemo!

 

cold start... no issues..... let the gas inject and goes just fine.

Hot starts I usually hit the black button to the RUN and immediately start it. It starts just fine then. If I let all the gas inject ... can almost be a smidgeon flooded. That is my experience.

 

Thanks to everyone for the replies andinformation...takes a little stress off me for sure. Great site. Ride safe !!

 

I have an 07 Electra Classic and it seems to start the same way.

LeonD

 

i had a similar problem when i first got the UC. did a SERT with a new map and it fixed that problem. have you had the recall recalibration done? know it was about heat, but possible they also changed other settings in the ECM, much like mine did with a new map.