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Hard starting when hot

Slowjoe

Slowjoe

Member
Recently my 2010 Dyna Wide Glide began acting strangely after long rides - say 60 miles (100 km) or more. When trying to start after a long ride, the starter engages, but cranks slowly, as if the battery is not charged. This is strange because it should be fully charged after a long ride. I understand that a 9 minute run is what an alternator requires to charge a battery.
Sometimes, when I flick the "kill switch" off and on again, that does the trick and although still sluggish, she fires up. I have checked the battery (two years and a few months since new) and the voltage at idle - 14.2 odd on my external digital voltmeter. Battery voltage is 12.6 odd with the Harley switched off.
She has 75 000 km (45 000 miles) on the clock. She mainly does longish trips and she does stand for maybe a fortnight at a time when I travel on Business. I dont have a dealer close by and have to be self reliant - am in the Eastern Cape South Africa, about a hundred and fifty miles from a major town. Any suggestions welcome. Many thanks.
 
Try doing a load test on a fully charged battery, see what the volts drop to when it's cranking.

  2. Step by Step Instructions for Testing Your Harley’s Charging System

    1. Battery Test:The battery needs to be a fully charged battery that has been load tested to ensure proper readings. If you are not working with a fully charged and functional battery, all other voltage tests will be incorrect. Most places like Auto Zone, Advance Auto, and Pep Boys will charge and test motorcycle batteries for free. Standing battery Voltage should be 12.5-13.2 DCV.

    2. Charging System Voltage Test: Start motorcycle, Measure DC Volts across the battery terminals (you should have a reading of approximately 13.2-15 DC Volts).

    3. Check Connections/Wires: Inspect the regulator/stator plug, and check the battery terminals for connection/corrosion. If everything seems to be in order, move on to number 4 below to determine if there’s a failed component.

    4. Stator Checks/Rotor Check: Each of the following tests isolate the stator & Rotor, If AC Output test Fails and Resistance Check, and Stator IB Test Pass then Rotor is at fault (Pull Primary covers and inspect rotor for damage).
    • AC Output Check:
    1. Unplug the regulator plug from the stator
    2. Start motorcycle and change Voltmeter to AC volts.
    3. Probe both stator wires with your meter leads.
    4. The motorcycle should be putting out approximately 18-20 ACV per 1,000 rpm. (Reading will vary depending on system, check service manual specification)
    5. Generic Specs:
    • 22 amp system produces about 19-26 VAC per 1,000 rpm
    • 32 amp system produces about 16-20 VAC per 1,000 rpm
    • 45 amp system produces about 19-26 VAC per 1,000 rpm
    • Stator Resistance Check:
    1. Switch your multi meter to Ohm x 1 scale.
    2. Probe each stator wires with meter leads and check resistance on meter.
    3. Resistance should be in the range of 0.1-0.5 Ohms. (Reading will vary depending on system, check service manual for specification)
    4. Generic Specs:
    • 22 amp system produces about 0.2 to 0.4 ohms
    • 32 amp system produces about 0.1 to 0.2 ohms
    • 45 amp system produces about 0.1 to 0.2 ohms
    • Stator IB test or Ground Check:
    1. Switch your multi meter to Ohm x 1 scale.
    2. Probe each stator wire with your positive lead on multi meter and the negative to ground.
    3. There should be no continuity to ground on either wire.
    4. If there is continuity to ground your stator is shorted to ground.
    5. Regulator Test: Each of the following tests isolates the regulator only, so if any of these tests fail, the regulator is at fault.
    • Identifying Wires:
    1. Battery Charge Lead– Wire going from regulator to battery positive.
    2. AC output leads– Wires coming from the Stator to regulator.
    3. Ground– Wire from Regulator to ground or regulator may be grounded via the physical bolting to chassis.
    • Regulator Ground Test: Insure the regulator body is grounded or grounding wire is fastened tight to a good ground (you should verify this by checking continuity from regulator body to chassis ground).
    • Fwd/Reverse Bias Test/Diode Test: This check is testing the Diode function to ensure it is regulating the AC current for the stator into DC Current.
    1. Switch multi meter to Diode Scale.
    2. Place your Multi meter positive lead on each AC output wire.
    3. Place your multi meter negative lead on the battery Charge wire.
    4. The meter should read voltage typically around .5 volts.
    5. Next, switch your multi meter leads putting the negative lead on the AC output wires and the Positive lead on the Battery Charge Wire.
    6. The reading should be Infinite.
    7. With your meter on the same setting, place your multi meter positive lead on the regulator ground wire or to the regulator directly, and then place your meter negative lead on the AC output leads.
    8. The meter should read voltage typically around .5 volts.
    9. Next, switch your multi meter leads putting the negative lead on the regulator ground and the Positive lead on the AC output wires.
    10. The reading should be Infinite.
    11. Note: Below is a table to show the readings:
    Positive Lead Negative Lead Reading
    AC output 1 Battery charge lead Voltage
    AC output 2 Battery Charge Lead Voltage
    Battery charge lead AC output 1 ∞
    Battery charge lead AC output 2 ∞
    Ground AC output 1 Voltage
    Ground AC output 2 Voltage
    AC output 1 Ground ∞
    AC output 2 Ground ∞
    Replacement Components
    Batteries
    350-430 (97-09 FLT, FLH, FLHT Dressers)
    350-431 (82-94 FXR, 84-90 Softail, 71-86 FX, 79-96 XL)
    350-432 (91-09 Softail, 97-09 Dyna, 97-03 XL)
    350-433 (80-96 FLT, FLHT, 93-96 FLHR)

    Stators:
    380-864 (L84-90 XL)
    240-556 (91-06 XL)
    381-259 (70-75 Big Twin 15 Amp)
    381-084 (76-80 Big Twin17.8 Amp)
    381-260 (81-88 Big Twin 22Amp)
    381-202 (89-99 Big Twin 32 Amp)
    381-596 (00 Softail, 99-03 Dyna)
    381-594 (99-01 Touring)
    381-595 (02-05 Touring)

    Regulators: (Offered in Chrome and Black, Black Part numbers listed below)

    380-798 (84-85 XL)
    381-177 (86-90 XL)
    381-014 (91 XL)
    380-797 (92-93 XL)
    380-485 (94-03 XL)
    381-835 (04-06 XL)
    383-089 (07 XL)
    381-252 (70-75 Big Twin)
    381-328 (76-80 Big Twin)
    381-327 (81-88 Big Twin)
    381-277 (89-99 Big Twin)
    381-605 (00 Softail)
    381-603 (97-01 Touring)
    381-606 (00-03 Dyna)
    Rotors:
    380-373 (70-06 Big Twin 18, 22, 32 Amp Systems)
    380-374 (95-06 Big Twin 38 Amp Systems)
    380-375 (97-05 Big Twin 45/48 Amp Systems)
    383-640 (84-90 XL)
    383-641 (91-03 XL)
    383-642 (04-09 XL) Welcome look here

    Freewheeler.eml


    Jeff Klarich, Jun 2, 2017Report
    #8+ QuoteReply
    HD4ME! likes this.

  3. Ricky-bMember
    7

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    Wow thanks jeff for all the info, The first thing I did was get a new battery. But ya I need to check all the connections (parts )tks


 
Checked the stats with a multimeter. About 13 v battery when the ignition is off., picks up a bit when at idle and only drops to 11v during startup. Anyway, thoroughly cleaned the positive terminal connection on top of the starter motor, which was pretty rusted. Still a little hard to start as in having to hit the starter button twice when hot, but better and mostly starts first time. new issue... rattle maybe imagination.. maybe camchain rattle... high mileage. will check heat shield and replace the screw thread clamps before I open her up..
 
At 45K miles, unless the head breathers have been externally vented, there could be enough carbon build up on the pistons to increase cranking compression to a point that is causing this issue. If that is the case, eventually, the battery will not last its full service life.

Suggest that the OP run some Seafoam through the motor and blow out as much carbon as possible. There is plenty of "how to" instructional information on the internet. I would give the motor a treatment, ride 100-200 miles and treat the motor again; rinse and repeat until the carbon stops blowing out the exhaust. It will come out and in visible chunks.;)
 
That makes great sense. Noticed a bit of black smoke on cold startup. I shall do the seafoam cleanup and report back Compression is very high. Many thanks much appreciated!
 
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