Hard start when bike is hot
#11
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ElectraJim (10-05-2016)
#12
How did you measure the voltage you listed in your original post?
A battery at rest that measures 11.9 volts is only at between 40% - 50% state of charge. A 14.7 volt reading with the bike running above 2000 rpm is the voltage being put out by the regulator, not the battery voltage per se. It is actually a bit high, the normal regulator output should be between 14.2 and 14.5 volts. However, the volt meters in the faring are notorious for being inaccurate.
I'd check all the wires and connections and have the battery load tested.
A battery at rest that measures 11.9 volts is only at between 40% - 50% state of charge. A 14.7 volt reading with the bike running above 2000 rpm is the voltage being put out by the regulator, not the battery voltage per se. It is actually a bit high, the normal regulator output should be between 14.2 and 14.5 volts. However, the volt meters in the faring are notorious for being inaccurate.
I'd check all the wires and connections and have the battery load tested.
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ElectraJim (10-05-2016)
#13
I've hunted around the forum a bit and couldn't come up with an answer to this. Bear with me, I'm still pretty new to Harley Davidson bikes.
It seems like my bike starts a bit hard after I've been riding and the engine is hot. Bike starts very easy when it's cold.
I've checked the battery and it sits at about 11.9volts. When running, it's at 14.7. I believe the battery is in good shape and I always keep a tender on it when I'm not riding for extended periods of time.
When I start it after riding, it seems to hesitate for a second and cranks over just fine. Every time I start it when hot, it's like it's in the middle of a compression stroke.
Is this normal or should I be looking at something else?
It seems like my bike starts a bit hard after I've been riding and the engine is hot. Bike starts very easy when it's cold.
I've checked the battery and it sits at about 11.9volts. When running, it's at 14.7. I believe the battery is in good shape and I always keep a tender on it when I'm not riding for extended periods of time.
When I start it after riding, it seems to hesitate for a second and cranks over just fine. Every time I start it when hot, it's like it's in the middle of a compression stroke.
Is this normal or should I be looking at something else?
1st is your slow starter / slow motor turn over when the motors hot is not a starter clutch issue,it's grinding of the stater & or the starter clutch cutting out before motor starts etc that are signs of a worn/bad starter clutch.
As long as you have verified (which is important) all connections in starting & charging systems are clean & free of rust & corrosion along with also being tight & in good cond then a battery thats a bit tired or just lower output (CCA) battery along with a starter getting a bit tired too are what generally cause slow cranking esp when hot starting post fueling up on a hot summer day.
It would not be a bad idea to have the starter tested (while still on the bike) for amps drawn when cranking the motor over when it's hot to see what cond its in & replace if required.
If you find the starter is tired replace it and it that fixes the hot start issue with the current battery thats great.
But if you find starter is tired thru testing then replace it and motor still hot starts slow or if starter passed testing then i'd next rec fully charging the current battery and then having it " properly load tested " to see how many CCA's it's got vs spec.
Hot HD's motors (like post fueling up on a summer day) are sometimes hard to turn over in that situation and even though you feel the current battery in your bike tested ok the fact is it can still not be up to the task of spinning a hot HD v-twin esp when the motor/starter & battery are heat soaked in summer heat.
Been there done that.
So if a new starter didnt help hot start issue or current starter tested ok i'd replace the current battery with Yuasa's maint free fact activated GYZ32HL battery thats got a higher then stock 500cca rating for only $132 to your door from Phatperf.
I installed that battery in my 09 FLHTCU and it starts it great even when hot post fueling up on hot summer days too.
BTW,if your motor is modded (esp bigger bore/more cubes with higher compression) i'd rec installing hi trq aftermarket starter along with a Yuasa 500cca battery both at the same time.
Good Luck.
Scott
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ElectraJim (10-05-2016)
#14
If you continue to start the engine with a weak battery or loose connections, you will accelerate your starter wear. If your starter is good now, but you have a starting circuit issues, your starter will soon be on the list of things to replace. Starters worst enemy is hi resistance such as an under performing battery.
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ElectraJim (10-05-2016)
#15
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ElectraJim (10-05-2016)
#16
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ElectraJim (10-05-2016)
#17
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ElectraJim (10-05-2016)
#18
How did you measure the voltage you listed in your original post?
A battery at rest that measures 11.9 volts is only at between 40% - 50% state of charge. A 14.7 volt reading with the bike running above 2000 rpm is the voltage being put out by the regulator, not the battery voltage per se. It is actually a bit high, the normal regulator output should be between 14.2 and 14.5 volts. However, the volt meters in the faring are notorious for being inaccurate.
I'd check all the wires and connections and have the battery load tested.
A battery at rest that measures 11.9 volts is only at between 40% - 50% state of charge. A 14.7 volt reading with the bike running above 2000 rpm is the voltage being put out by the regulator, not the battery voltage per se. It is actually a bit high, the normal regulator output should be between 14.2 and 14.5 volts. However, the volt meters in the faring are notorious for being inaccurate.
I'd check all the wires and connections and have the battery load tested.
I have to confirm my readings again. I'll definitely get the battery tested and I'll check alternator output. Thanks!
#19
#20
+1 I was having this same problem on my '07 Ultra getting me worried that I'd not get it started after fueling up out in the sticks but doing this it has never failed yet.