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Ok, got the bike rebuilt. I go to start it and the solenoid sticks and burns up. So I got another solenoid. The solenoid sticks again. So I realize the battery might be weak. So I hook jumper cables to my car and try to jump start it. Well it cranks, but never stops cranking. Even when I let off of the button. It still cranks.
Starter run on occurs when the contacts in the solenoid will not open.
Replacing a starter because of run on would be like replacing a light bulb because it won`t go out…
Some things that can cause starter run on: Weak battery, poor electrical connections, bad solenoid, a problem with the pinion gear.
When the solenoid shaft is extended by the magnetic coils in the solenoid, it does two things: it engages the pinion gear into the ring gear, and it brings the electrical contacts together.
When the pinion gear drives the ring gear there is quite a bit of friction between the gears, but as the engine goes past a compression stroke there is a slight decrease in that friction, and that is when the pinion gear will retract when you let go of the button (when everything is working correctly).
When there is problem with low voltage, the engine cranks a little slower, and you don`t get much of a change in the friction between the gears, so the gear stays engaged, and that keeps the electrical contacts connected.
This can also happen if you crank the starter while the spark plugs are removed, the pinion gear won`t disengage because the friction between the pinion gear and the ring gear is constant.
I suggest cleaning all electrical contacts, inspecting the battery cables, or just buy new cables.
Check the condition of the solenoid electrical contacts.
Another way of eliminating starter run on would be to install a Ford type starter relay, these relays were used on some Harleys in the mid to late`70s.
The larger relay controls the battery current to the solenoid and motor, so when the start button is released, the current to the starter solenoid and starter motor is cut, and the starter will shut off.
Last edited by Dan89FLSTC; Apr 26, 2014 at 04:27 PM.
If part A is missing or part B is worn out...the solenoid can "stick" in the on position even if the solenoid is in good condition. Sometimes you need 2 thrust washers(part A) to keep it from hanging up.
after ya do all that-- replace the starter -- a starter that's been over heated generally sticks and will toast everything - had one not long ago-- dude swore the starter was good-- he just bought it -- yeah USED -- when cranked it would crank slow and stick and toast the wires and or solenoid
new starter -- end of problem - replaced battery after that ONLY because allballs says use a 310 cr battery --
hey could be a missing brass washer - seen that before also
Did this ever get resolved? I have the same issue with my 86 FLHTC, it was like this when I bought it and I've replaced solenoid, starter, starter shaft, starter clutch, bearing in the starter housing and the one in the outer primary as well. The cables look like they've been replaced and the battery is new? I've been a truck mechanic for 30 years this ones getting to me!
Did this ever get resolved? I have the same issue with my 86 FLHTC, it was like this when I bought it and I've replaced solenoid, starter, starter shaft, starter clutch, bearing in the starter housing and the one in the outer primary as well. The cables look like they've been replaced and the battery is new? I've been a truck mechanic for 30 years this ones getting to me!
Did you ever resolve this ...I'm the original owner of a 73' XLH Sportster with all the same issues...thanks, Rich
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