Stator issue fitting:

Robert Shaw · Saturday at 6:25 PM

Today I replaced a failing stator. After watching a thread from Chris Rooke, I started. Installed the new stator, and went to measure it from the rotor for clearance. After watching the video, .008 was recommended. I got the proper clearance at 12/6/9 side but at the 3 O'clock side , VERY tight, very tight .008 I tried hitting the stator as recommended to move it slightly, to gain the needed .008. After beating the crap out of it, got a little more,but not what it needs. If I broke one of the studs I would scream!!!!!!!! read another post about someone doing something with the studs. I'm not sure about attempting that? There has to be an easier way. Spent 4 hrs today, and no further ahead than when I started. CRAZY!! If anyone has an magic cure, I'm listening. Robert TN

seattle##gs · Saturday at 9:52 PM

If you have a dremel tool and lots of sanding rolls you can take off material in the tight spot. Pounding on it is a poor idea. Perhaps a sanding roll in a drill? A trip to HF or Lowes or home depot. Use a dust mask or respirator.
The stators all seem to be tight around 3 o'clock. I bought an oscillating spindle sander just for this job because I run into it often.

Torontonian · Saturday at 10:53 PM

seattle##gs said:
If you have a dremel tool and lots of sanding rolls you can take off material in the tight spot. Pounding on it is a poor idea. Perhaps a sanding roll in a drill? A trip to HF or Lowes or home depot. Use a dust mask or respirator.
The stators all seem to be tight around 3 o'clock. I bought an oscillating spindle sander just for this job because I run into it often.

Yes to this method . Work the holes more open .
Don't forget the original rotor will have lost a lot of magnetism after 50 or more years ...

o0norton0o · Sunday at 12:18 AM

Make sure the studs are threaded all the way in, then take a sharpie and mark the side of the stud in the direction it has to go to move the stator to the correct position.... If you mark the 3 o'clock stud, then mark the 9 o'clock stud too. Take them both out grip the threaded part in a vise with wooden blocks against the threads then slide a long pipe over the stud and give it a baby bend... just a little goose

, not a big oink

. It takes almost nothing to get a few thousandths. Do both studs in the direction the stator needs to go (indicated by the sharpie mark) Thread the 2 studs back in and remeasure the gaps... not... rocket... science repeat as needed..

Robert Shaw · Sunday at 8:11 AM

Thank you guys so much. I wish I could have posted this earlier, it would have saved me so much time and anguish. Need to measure the new stator, to make sure my banging didn't change any electrical properties within Also need to locate a primary case center grommet (the one that stator wires feed through) Mine was toast. Of course I have a giant box of grommets, but none are the size I need. Murphy's law. Thanks again so much! Robert TN

TJBaker57 · Sunday at 8:14 AM

Just a thought ..... when checking the clearance did you rotate the crankshaft a bit and recheck? Maybe several times? My old rotor was way out of round.

kommando · Sunday at 8:22 AM

Never use a hammer on the stator, the studs have a habit of cracking the alloy they are screwed into.

Fast Eddie · Sunday at 9:10 AM

Most folk Know my thoughts on this.

I simply get the rotor turned down so I have 20 thou clearance at the tightest point.

Then assemble using a strip of plastic milk carton whilst tightening things up just to make sure nothing closes up.

Problem solved forever.

Done this on all my bikes that run pattern Lucas stuff for years with no ill effect.

A sledgehammer to crack a nut perhaps, but it works for me.

o0norton0o · Sunday at 9:15 AM

kommando said:
Never use a hammer on the stator, the studs have a habit of cracking the alloy they are screwed into.

YES, You don't want to try to bend the studs while they are engaged in the threaded boss of the inner primary case... That's a recipe for disaster... Also you don't need a lot of bend to get a few thou movement. Perhaps this is bad advise because it takes a little bit of common sense to accomplish...

WEM · Sunday at 2:01 PM

Fast Eddie said:
Most folk Know my thoughts on this.

I simply get the rotor turned down so I have 20 thou clearance at the tightest point.

Then assemble using a strip of plastic milk carton whilst tightening things up just to make sure nothing closes up.

Problem solved forever.

Done this on all my bikes that run pattern Lucas stuff for years with no ill effect.

A sledgehammer to crack a nut perhaps, but it works for me.

I have also had the rotor turned down by a machinist to get it to fit. Seems to work fine. No apparent loss of charging ability.

cliffa · Monday at 5:22 AM

Bearing in mind the number of folks who have had similar issues, I'm surprised that waisted studs haven't been made available by one of the suppliers.

Stephen Hill · 2026-09-15T11:07:13-0600

Pull the studs one at a time and find out which one is causing the interference.
It may be the case that all three holes/bolts are the problem.
While you have the studs out, check that none of them are bent.
Use a file to "move" the hole in the stator. Filing the laminations is tricky: the file tends to bind. PInch them in a vise and they file better.
Or use a drill to oversize the holes to give you clearance. The functional equivalent of waisted bolts.

YING · 2026-09-15T13:49:14-0600

Stephen Hill said:
Pull the studs one at a time and find out which one is causing the interference.
It may be the case that all three holes/bolts are the problem.
While you have the studs out, check that none of them are bent.
Use a file to "move" the hole in the stator. Filing the laminations is tricky: the file tends to bind. PInch them in a vise and they file better.
Or use a drill to oversize the holes to give you clearance. The functional equivalent of waisted bolts.

That works but make sure you do it in a vise with it as close as possible to the hole you want to enlarge.Don’t ask me how I know!!
Mike

nortonmargie · 2026-09-15T14:02:32-0600

Lacking any machining tools I sanded (wearing mask) the rotor by hand to get it to fit, repeatedly checking clearance. It took me a week, but it worked. It sounds like pretty much all rotors are out of round

Stephen Hill · 2026-09-15T15:28:41-0600

YING said:
That works but make sure you do it in a vise with it as close as possible to the hole you want to enlarge.Don’t ask me how I know!!
Mike

Agreed. Just like filing the holes, drilling the holes is tricky. The laminations want to spread and grab the file or drill bit.

o0norton0o · 2026-09-15T16:25:53-0600

I turned one of my extra rotor's down... It took about a minute.... then flipped it 'round and finished the cut, so 2 minutes...

TJBaker57 · 2026-09-15T22:25:37-0600

I am nowhere near this potential issue yet on my rebuild.

But given the cost of a stator if I screw up enlarging a hole vs the cost of a stud,,,, I think I'd try waisting the stud(s) first!!

Tornado · 2026-09-16T00:14:05-0600

See Norm White's recommendation for sorting the stator/rotor gap by shaving down the studs (by machining or perhaps by rotating in drill and using a flat file), rather than attempting to enlarge the holes. If studs show any bends after removing, replace them.

cliffa · 2026-09-16T00:52:38-0600

o0norton0o said:
I turned one of my extra rotor's down... It took about a minute.... then flipped it 'round and finished the cut, so 2 minutes...

Two minutes - if you have a lathe

YING · 2026-09-16T01:51:12-0600

TJBaker57 said:
I am nowhere near this potential issue yet on my rebuild.

But given the cost of a stator if I screw up enlarging a hole vs the cost of a stud,,,, I think I'd try waisting the stud(s) first!!

TJ,
If you encounter clearance problems,you can’t go wrong with FastEddies solution.Do it once and forget about it.
Mike

Stator issue fitting:

Robert Shaw

seattle##gs

Torontonian

o0norton0o

Robert Shaw

TJBaker57

kommando

Fast Eddie

o0norton0o

WEM

cliffa

Stephen Hill

YING

Pittsboro,NC

nortonmargie

Stephen Hill

o0norton0o

TJBaker57

Tornado

cliffa

YING

Pittsboro,NC

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