starter stays on

[quattrorunner]

Last night I installed some headers on my 77 turbo engine that is installed into my 77 911s. Before I removed the stock headers, I cleaned the fan with some degreaser and some water and didn't get much wet other than the fan and inside the fan but not a jet of water, more like a soft rinse. But anyway, then I started the car again to put it in the garage, no problems at all. I removed the heat exchangers, removed the turbo,cleaned a little tightened some hidden things, and installed the headers, replaced the turbo which had to relocate some things as location changed slightly, no big deal. adjusted the length of my wide band oxygen sensor, rearranged the scavenge oil line and rertightened and buttoned up.
Went to start it,and found a flange needed tightening so went to turn it off but it didn't want to turn off. Engine did, but the starter had been running along with that loud exhaust leak. It was confusing at first not knowing what was going on. Ignition was off, engine was not running but the starter was turning the engine still. Had to remove the battery positive to get it stopped.
Any ideas please?

[quattrorunner]

Also, it doesn't want to start or turn over at all. Turned the key the first time and nothing other than pump. moved some things in the fuse panel, and moved some wired around the starter itself and it started slowly but ran like I said.
This morning, nothing again. hope that helps.

[TonyGO]

Happen to me ,check starter wires,one of mine was grounding out,hope i was helpful.goog luck.

[john walker's workshop]

a chewed ring gear can grab the starter gear and as long as the bendix it extended, the solenoid contacts are giving 12V to the starter. it spins a zillion RPM and is killed. so check that ring gear through the starter hole, all the way around. needs to be smooth, not ragged.