as im sourcing to replace my starter and they cost around $100 to get another used one. good thing my friend has a spare starter. been looking for good info but not many of them so here it is just a share for people who looks for alternative for replacing their shot starter.
THINGS THAT YOU NEED
8mm
10mm
ratchet
89-90 starter (can source out from your local junkyard or a friend who crashed their 240...LOL)
KA starter on the LEFT and SR on the right
Unbolt 2 bolts from the solenoid using 10mm socket wrench and 8 mm for the other 2 bolts. then swap the upper portion from ka to sr.
when you open it up. be careful just in case not familiar with it things do fall off. when you check from the inside you will see 3 gears from the bottom part of the starter and a ring like gear inside the upper part but i think there is a cap cover for everything its just my sr came off like that so i just explained it.
check the ring gear for any wear on the outer bushing/rubber. i have mine from the sohc starter worned out so i used mine from my sr.
this pic below when i tested it from kragen see it works and i didnt put any grease on it thats when i hear that grinding sound.
when you put things back together. i recommend putting new grease to the gears so itll ease that painful grinding sound.
then attached the ring gear together with 3 small gears.
put the cover back and make sure the holes for the bolts are aligned. if you checked on the site of the starter there is a marker that aligns the bolts so you wont have a hard time adjusting it to make the bolt go in.
for the solenoid
there is 3 parts from the under the solenoid. a retaining clip, a washer, and a metal piece that pulls the trigger to get the pinion to mate with the flywheel to get it start.
the trigger from the bottom part of the starter
re assembling it. make sure that the trigger from the bottom part of the starter gets inside the metal piece.
then screw back those 4 bolts but then overtightened it.
there you have an alternative starter now.
as for everything. it works and as i tried performing this swap. engine is out of the car so i had to run wires to crank my motor. but it should work fine. i have a redtop s13 so it should work for s13 blacktop as well. not so sure about the s14 and s15.