Harley starter current

Thread Starter

#12

Joined Nov 30, 2010
18,182
Does anybody know the starter current for a Harley Davidson motorcycle?
I think I should put a fuse in, but it's not a, "for sure" thing.
 

Thread Starter

#12

Joined Nov 30, 2010
18,182
How thick are the cables on the starter motor?
Looks like about #4 AWG
Why do you think you need a fuse??
Sometimes, when the battery is low, the starter solenoid fails to release and the starter motor cranks until the battery is dead. The solenoid being mechanically stuck, you have to kill the main supply to stop the failure mode. Still haven't decided...big old switch on the battery or a fuse.o_O
Starter solenoid out of a Ford with a panic button.o_O
 

ISB123

Joined May 21, 2014
1,238
#4 AWG Can carry around 70-80A. So it should be somewhere around those numbers when under heavy load.

Clamp multimeter would do you good.
 
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Thread Starter

#12

Joined Nov 30, 2010
18,182
Sounds to me the solenoid is not working properly.
That is true. Unfortunately, replacing the solenoid only gets me the same solenoid.
This isn't a problem on one motorcycle, it's a design flaw in the solenoids.
#4 AWG Can carry around 70-80A. So it should be somewhere around those numbers when under heavy load.
This cable isn't designed as a continuous current wire. It's designed for x number of volts of loss at y number of amps. Standard building codes do not apply to this design. The length being about 14 inches.
 

Thread Starter

#12

Joined Nov 30, 2010
18,182
4023 ft/ohm in a #4 AWG cable.
248 uohms/ft
Theoretically 290 micro-ohms.
3448 amps per volt.
No help from the math.:(

0.037 volts per 110 amps.

Then again, most of you know it's difficult to get under 1/10th ohm in the connections.
 
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tcmtech

Joined Nov 4, 2013
2,868
I'm going with the ~100 amp estimate as well. It's about what my 22 HP B&S engine on my lawn mower draws.

A two cylinder Harley and two cylinder B&S are about the same right? :confused:
 

Thread Starter

#12

Joined Nov 30, 2010
18,182
I'm going with the ~100 amp estimate as well. It's about what my 22 HP B&S engine on my lawn mower draws.

A two cylinder Harley and two cylinder B&S are about the same right? :confused:
LOLZ.:D
I don't think they are similar, but 110 amps seems like the right area.
 
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Thread Starter

#12

Joined Nov 30, 2010
18,182
Gotta go for a couple of hours. Back at 11 pm, my time.

I suppose I could get a DC ampmeter, but I'm too cheap to buy one for one job.
 
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Lestraveled

Joined May 19, 2014
1,946
Still haven't decided. Maybe a long duration current compared to the usual 1-2 seconds of cranking.
Harley's always start the first time......... o_O A fuse would just contribute to a different kind of problem.

Why do the solenoids stick? That is the problem you want to solve.
 
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