Z1 vs Z900 vs Z1000 Alternator rotor

Some of you might remember I twisted my crankshaft on my Z1R 1978 some time ago. I had an as new condition crankshaft from either a Z1 or Z900.
My problem is I fitted the rotor onto the crankshaft which is supposed to fit the Z900 and Z1000 - search RO99 rotor. The problem is that the rotor has sheared the key and went loose on me (no damage to shaft taper or the rotor) but I am worried there is a difference in the taper between the 73 Z1 and the Z900??.

If it has a key, it's the same.
Steve

swest wrote: If it has a key, it's the same.
Steve

Thanks Steve _The crank (I have currently) has a key, the (None OEM RO99) rotor I have also has a key but it also fits the Z1R crank (without the keyway)
My concern is that the 1973 Z1 has a different taper to either the Z900 (1975 to 76) and the Z1000 (1977 to 78).

They are all the same.They also have a tendency to come apart and get loose.
Steve

swest wrote: They are all the same.They also have a tendency to come apart and get loose.
Steve

Looks like I need to lap the bastard on or weld it (joking).
Thanks for your help

I've had trouble like that too. I might do the same.
Steve

mark the end of the crank up with some dykem or a felt tipped pen and put the rotor on and twist it and see what kinda contact it's making.

leon

From Z1 to Z1R , Keyed or keyless, The small rotors are all the same taper.
Only difference being the keyed cranks take an 8mm bolt and the keyless 10mm bolt.
Any of the small rotors will fit your Z1R crank. ( as long as it's not the MK2 motor ).
Best thing to do is lightly lap the rotor with some fine grinding paste and once all traces of paste are removed assemble DRY..
Do not use any sort of Loctite on the taper ,only on the bolt.

zed1015 wrote: From Z1 to Z1R , Keyed or keyless, The small rotors are all the same taper.
Only difference being the keyed cranks take an 8mm bolt and the keyless 10mm bolt.
Any of the small rotors will fit your Z1R crank. ( as long as it's not the MK2 motor ).
Best thing to do is lightly lap the rotor with some fine grinding paste and once all traces of paste are removed assemble DRY..
Do not use any sort of Loctite on the taper ,only on the bolt.

Zed1015/351, I have to admit I stuck bearing loctite onto the taper which might've been a hindrance rather than help. I will grind paste the shaft (luckily I did no damage this time), The other mistake I made was fitting a tighter (there are three widths) starter washer that goes to the outer crank bearing (it has a rubber seal included), this might've prevent the rotor from going hard onto the taper.
Again thankyou all, you've been a great help, mainly answering the question about the crankshaft taper being the same on all models.

Just for your info the RO99 rotor I am using doesn't appear to output as high a voltage as my OEM, with the OEM rotor the regulator put out a constant voltage of around 14V with no load (over 3K rpm) and 13.5V with lights ON, this unit is struggling to hold 12.5V and 13.4V max no load. But saying that it won't come apart like the OEM.

Weak magnets?
Steve

The lower output may well be due to weaker rotor magnets as SWEST rightly suggests.
The fitting of the thicker damper won't prevent the rotor from seating but if the damper is too thick tightening the rotor can dish it and cause it to bind the starter clutch gear .
This can cause the starter motor to be driven once the engine starts.
It is better to have a thinner damper and some clearance.

The shaft had a bit of damage due to the keyway being sheared. I lapped it in the best I could, I tried it by doing the bolt up gently, it required the puller to take it off (not that much force). I cleaned and dry assembled the complete unit using the thinner rubber washer, checked that the rotor was locked onto the shaft, refitted the bolt with Loctite,
I did not fit the woodruff key at this stage, I'll recheck the rotor in a month or so (unless it loosens before then).