Hi All, I'm restoring an 1985 Ironhead Sportster. I've hooked it up to a brand new battery, so power is good. Checked the direct line to the solenoid and also good.

The starter button gave me a single click coming from the relay. But nothing else happened. I changed over the contacts in the solenoid and found if I manually pushed the plunger in it would spin and whine but not engage/turn over the engine. I changed the starter relay and now the plunger activates from the button, but still the same spin and whine.

I pulled the primary cover and can see it spinning the clutch and primary chain but not turning the engine over. (Video attached) I pulled the starter and it stank of burnt wiring. Is the starter toast, or is the smell from the cranking and the starter is actually working? Is it the starter clutch that's the issue? I don't think the engine's seized as I can jack the back end up and rotate the rear wheel in gear, so things seem to be moving in there. Just not engaging with the starter. Can anyone help please?

Thanks guys...

 

There seems to be no resistance to rotating which I think means starter OK but engine sprocket not transmitting the torque to the engine, Stripped out splines?

 

see if you can rotate the engine via crank bolt.

 

I've tried cranking the bolt in and out of gear and also just rotating the wheel and going through all the gears. Have pulled the spark plugs and shining a torch in there and nothing's moving... is it looking like engine seized or as above, maybe stripped splines somewhere - i'm going to have to pull the other case off and have a look aren't I? Either way is looking less like the starter clutch? I've just ordered one so will cancel that order if it's not that - thanks for advice so far guys...

 

So pull the other side casing off and check gears for anything obvious?

(sorry this was meant to be relying to Baird's comment)

 

disconnect battery
remove sprocket shaft nut
rotate clutch while looking at the sprocket shaft, does it move with the sprocket or remain stationary?

 

Just tried, it moves with the sprocket. Wasn't moving a massive amount with the clutch, looked stationary at first, but then rotated with sprocket. (vid attached)

 

wrong sprocket. you need to confirm the motor sprocket (smaller sprocket on triple row chain) also remove timing plug to observe if flywheel moves.

 

# 25 I hope you have a FSM to reference for working on tghis machine

 

Thanks @Baird I do, had a read and then gave it a try, can't get that nut to budge at all, tried following the manual, put it in gear, foot on the brake, wheel on the ground etc. to lock the transmission, got the torque wrench and a pole on the end of that and won't budge. I thought I'd got it to give but it was the whole thing slipping while the rear wheel was locked.