Multiple Motor Issues

Some things to look for, if it Helps. Note the 72-78 Z1/KZ parts on the Left, smaller stuff. Yours to the Right and be expecting to be looking at upon removal, bigger stuff. Especially look at the area where those Big rollers ride-freewheel or       clamp to when starting. The KZ 16-pin crankshaft during 79-80 shared similar of what Yours resembles but rotor was slightly different but still used the "internal" stator too. Have fun..Again.

I've read many posts on removing the rotor and I think it boils down to this;
Put a bearing ball in the bolt hole.  I got a 3/8" one from Ace Hardware unfortunately chrome plated  rather than hardened.
Thread a bolt into the until tight then hit with an impact wrench. I don't have axles and such so I'll buy a 12mm fine thread bolt longer than the factory bolt.
The rotor should come loose.
It this correct?

Thee correct factory bolt isn’t expensive and is hardened so more durable

Just a note, there are different thickness rubbers available to get the correct amount of “drag” on the starter gear

Well I messed up big time.  Not really understanding how it all comes apart I got too small a bearing and it went all the way thru the crankshaft and is now hopefully sitting in the oil pan.  I got a larger bearing and see that I need a bolt that is about 16mm that treas into the rotor.  Now I understand using axles etc,  I'm not sure which thread so I have ordered both  coarse and fine thread hardened bolts. I don't mind taking the oil pan off as while using an extension magnet trying to fish the small  ball out I came out with a couple of flakes of steel. 

I believe the OEM tool is M18x1.5 (RH)

Got the proper bolt 18mmx1.5  from McMaster Carr and the rotor popped of with a 1/2" bearing available at Ace Hardware using my 1/2" battery impact tool.  I found some hopefully minor spawling of the crankshaft taper and the rotor and that the 3 bolts that hold the sprag clutch to the rotor are all sheared off.  I only found 2 of the bolt heads so I'll assume the third is in the crank case along with the bearing.  Since the bolts appear to be hardened and a new rotor is almost $700 I'm taking it and the rest of the motor into a race car machinist who can get the bolts out safely and hopefully lap the crank and rotor to get a good fit  My only possible explanation for shearing the bolts is that I may have tried to restart the motor without the clutch in and the gearbox in 3rd,  I was rather busy at the time wondering what had happened, coasting to a stop, getting off the track  and making sure I didn't get run over by another car.  Since I'm in there even though nothing in the clutch looks particularly worn I'm wondering if I should get a new sprag clutch at about $180, get a rebuild kit for about $50.  The large drive gear does have some wear on the face. 

Personally (only my opinion) I would just replace the springs and rollers in the clutch, the gear may be worn but given it generated enough torque to break the bolts I don't think the wear is an issue. The broken bolts are likely a result of them vibrating loose over time (use thread locker on re-assembly)

Ordered a new starter clutch as the old one was warped and considerably beat bolt head flying around. It took two light cuts to clean it up.  Considering it takes about 3 hours to get the motor out for access we deemed it better to just buy a new one as the "stack" height would change.  Lapping the crank pin and rotor went quickly and well, but may again affect the stack.  I have the middle thickness  back washer and hope it works as the thinner on is not available from partzilla.

Well back again.  Doing reassembly and I need to torque both the sprocket bolt and the rotor/clutch assembly while the motor is in the stand as due to lack of space the cover has to be on before installation in the car.  the only way I can think of torquing the rotor bolt is to stuff two cylinders full of rope in order to lock up the motor.  I would imagine I could do the same with the sprocket. The book call for the sproket to be torqued to 94 ft/lbs, but I had to get a different bolt as the original one gone and the one that came out not very good.  The replacement bolt is a flange head 10mm Gr12.9 which is only recommended for 83 ft/lbs.  I'll use blue Locktite on both, does that sound like a reasonable way to proceed?

MJinCO wrote:

Well back again.  Doing reassembly and I need to torque both the sprocket bolt and the rotor/clutch assembly while the motor is in the stand as due to lack of space the cover has to be on before installation in the car.  the only way I can think of torquing the rotor bolt is to stuff two cylinders full of rope in order to lock up the motor.  I would imagine I could do the same with the sprocket. The book call for the sproket to be torqued to 94 ft/lbs, but I had to get a different bolt as the original one gone and the one that came out not very good.  The replacement bolt is a flange head 10mm Gr12.9 which is only recommended for 83 ft/lbs.  I'll use blue Locktite on both, does that sound like a reasonable way to proceed?

What book are you using ? the below is from the FSM in the file-base on this site. Also below is the correct "rotor holding" tool. I really don't like the "ram it full of rope" idea (just my opinion)

Progress, both good and not so good.  I got a spanner wrench set by Orion from Amazon that fits the rotor perfectly,  On the other hand when the unit is assembled the starter gear spins freely, I have measured the gap and it appears that the clearance is mo.4mm or .015"  the 8.3 spacer bushing is NLA so it appears my only choice is to make spacer and put it between the rotor and the clutch or lap the rotor to crank pin to move the rotor a bit up the taper.