Starter on 83 fxrt spins but wont engage

starter failing --wiring / connector ---ignition switch failing-safety switch ---need a meter to test when problem occurs again

Hi Anonymous

What I believe you've said is that you turn the key to start, the engine turns over for a second, then you just hear the starter spinning but no engine turn over. Yes?

Then you took it to Autozone and tested it and it stayed engaged during the test. The differences, possible or real here, are the load on the starter gear end, and the electricity driving it.

There are a couple things happening in the start cycle. The motor starts spinning and the solenoid pushes the spinning gear forward to engage the toothed edge of the flywheel. If the solenoid doesn't push enough, the gear won't engage. So, one thought is that there's an issue with the solenoid - it may push the gear out just fine, but lack power to keep it pressed forward if there is back-force from the engine.

If you have a poor connection to the battery, the solenoid may not draw the current to keep the gear engaged. Checking the hot (red) wire both at the battery and where it attaches to the starter is the primary diagnostic there. Even if the battery has a good charge, the current draw if starting is the heaviest load it encounters in a typical day of driving, so the ability of the battery to dump that charge quickly in a pulse of high current is also important, and non-corroded, tightly connected wires help.

The starter gear also has a clutch in it - akin to the freewheel on the rear of a bike, or a ratchet. This lets the gear spin faster than the starter motor once the engine catches, so that the engine doesn't essentially grab the engaged starter motor and spin it waaay too fast. letting back on the key lets the fast spinning gear disengage without trouble. If there is an issue with that clutch/ratchet, that might also be allowing the gear to spin without it actually pushing - like the clicker in a ratchet sticking so that it'll spin either way.

After that.... there is likely both a relay and a fuse for the starter. Not a bad idea to check that neither is blown, or, in the case of the relay, looking sort of browned and cooked.

Hope this helps!
D

it engages because you hit the button, unshimmed jackshaft to outer primary, battery is low

The bendix may not be pushing the gears to engage the flywheel. Take out the starter and have it tested.

INDICATES A SNAPPED KEY OR A WORN GEAR.

What ever it is it sounds like the starter Bendix isn't engaging. Need to know if it is engaged by a solenoid or centrifugally engaged.
Gillight

If the starter motor spins at high speed, but doesn't turn the engine until you whack it, the starter gear is not engaging the flywheel. Probably the engagement fork or the starter gear is worn out or sticky, or the solenoid isn't pushing it far enough.

Starter motor spins, but does not engage

1. Check the starter motor for a seized or binding pinion gear.
2. Remove the flywheel inspection plate and check for a damaged ring gear.

if the starter spins but does not engage flywheel. then its the starter solinoid thats bad. its on top of starter, when key is turned to start, the solinoid is activated, and it pushes the gears out to make contact with flywheel to start vehicle. so the solinoid just spins with out kicking out to flywheel. change solinoid or get another starter. have a good day !

Bad switch or Solenoid. depending on the bike.