What Did You Do With Your Commando Today?

HouTexNorton said:
Many seem to have this problem (at least that talk about it). When I bought my 14.5 amp 3 phase stator with a new rotor from Matt I used a cut-up plastic water bottle that measured 0.01" thick to make sure I had the proper clearance between the rotor and stator (I have Matt's e-start so the stator mounting is different than stock). I tested it at idle and the clearance and charging was fine. I went for a ride and noticed that my IC charge warning light was showing no charging after a while. When I got back home and pulled the stator it was completely melted and destroyed. I had Matt turn down the rotor 0.01" all around and installed a new stator. Same installation procedure with no issue at idle, but when ridden it was rubbing again, but not as much. I used a Dremel tool with a sanding drum to clean up the inside of the stator and remove a little of the epoxy material all around being careful not to damage the magnets. Finally all is well, but I would guess that I now have about 0.025" of clearance and still get good charging. I measured the crankshaft with a dial indicator and am not getting any noticeable deflection when manually turning it, but who knows if there might be some when it runs and heats up. Maybe a slight bearing issue, although the engine has less than 1,000 miles since completely rebuilt by Classic Bike Experience.
Click to expand...
You are fortunate. I have melted 2 stators in the last week! I had .013 minimum clearance at ALL positions on the rotor.Started bike,checked charge rate,all good,went for 10 mile ride,came home and removed primary cover and re-checked the clearance.Everything good.Then went out for 50 miles or so and removed cover again to see another melted stator.This whole process has happened twice now and I have absolutely no idea of what is going on. I went over every check on my install along with a new regulator/rectifer to see if that was my grief. I am at wits end on this as they don’t give those stators away.No noticeable run-out on the crank.Any suggestions??
Mike
Same set-up as HouTex
 
YING said:
You are fortunate. I have melted 2 stators in the last week! I had .013 minimum clearance at ALL positions on the rotor.Started bike,checked charge rate,all good,went for 10 mile ride,came home and removed primary cover and re-checked the clearance.Everything good.Then went out for 50 miles or so and removed cover again to see another melted stator.This whole process has happened twice now and I have absolutely no idea of what is going on. I went over every check on my install along with a new regulator/rectifer to see if that was my grief. I am at wits end on this as they don’t give those stators away.No noticeable run-out on the crank.Any suggestions??
Mike
Same set-up as HouTex
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Well (obviously) my first suggestion would be to increase your gap to .020.

But are you sure it’s rubbing? Or is it doing what Grant Tiller talks about lot about?
 
Fast Eddie said:
Well (obviously) my first suggestion would be to increase your gap to .020.

But are you sure it’s rubbing? Or is it doing what Grant Tiller talks about lot about?
Click to expand...
Are you talking about rectifiers doing something silly and shorting things under certain circumstances?
If that's the case then it could be verified by setting up the new stator, but not connecting it up to the regulator.
Have a fully charged battery and go for the same 50 mile trip (daytime and minimise light use). If all's good, then what you say about Grant Tiller's findings may be the case.
Cheers
 
robs ss said:
Are you talking about rectifiers doing something silly and shorting things under certain circumstances?
If that's the case then it could be verified by setting up the new stator, but not connecting it up to the regulator.
Have a fully charged battery and go for the same 50 mile trip (daytime and minimise light use). If all's good, then what you say about Grant Tiller's findings may be the case.
Cheers
Click to expand...
I can’t recall all the details now, but Grant basically believes that the modern trend to fit high powered stators and low energy LED bulbs etc leaves the stock system unable to handle the power and heat.

Hence the use of shunt type regulator units like the Shindengen.

And as much as I’m a fan of belt drives, a dry primary also deprives the area of some oil cooling, and perhaps even lubrication in the event of some mild rubbing. Neither of these is a root cause, but possibly contributory factors to the above heat issue.

Then add tighter than needed clearances into the mix and maybe it’s all just too much, even though there’s nothing actually ‘wrong’ or faulty.
 
YING said:
You are fortunate. I have melted 2 stators in the last week! I had .013 minimum clearance at ALL positions on the rotor.Started bike,checked charge rate,all good,went for 10 mile ride,came home and removed primary cover and re-checked the clearance.Everything good.Then went out for 50 miles or so and removed cover again to see another melted stator.This whole process has happened twice now and I have absolutely no idea of what is going on. I went over every check on my install along with a new regulator/rectifer to see if that was my grief. I am at wits end on this as they don’t give those stators away.No noticeable run-out on the crank.Any suggestions??
Mike
Same set-up as HouTex
Click to expand...
You could have a problem with the inner primary chaincase alignment changing when you put the outer cover on. Try this, check clearance on stator, then use a spacer on the centre stud and tighten the nut that secures the outer cover as if cover was fitted. Check the stator clearance again. If it has changed you don't have correct amount of shims behind inner chaincase and it's distorting when you fit outer cover.
 
Nortoniggy said:
You could have a problem with the inner primary chaincase alignment changing when you put the outer cover on. Try this, check clearance on stator, then use a spacer on the centre stud and tighten the nut that secures the outer cover as if cover was fitted. Check the stator clearance again. If it has changed you don't have correct amount of shims behind inner chaincase and it's distorting when you fit outer cover.
Click to expand...
Iggy
I was very careful when setting up the shims on the center stud when I last had it apart but will check it again first thing today.Good idea on that which I would never have thought of.Center nut was never over tightened but who knows.Also I have LED bulbs everywhere thinking that was the way to go for being easier on the charging system.At this point any suggestions are appreciated.
Mike
 
YING said:
Iggy
I was very careful when setting up the shims on the center stud when I last had it apart but will check it again first thing today.Good idea on that which I would never have thought of.Center nut was never over tightened but who knows.Also I have LED bulbs everywhere thinking that was the way to go for being easier on the charging system.At this point any suggestions are appreciated.
Mike
Click to expand...
Mike, if rubbing between the stator & rotor is the issue surely there would be witness marks on the steel parts to prove that?
It would help to identify if you're chasing a mechanical or electrical problem.
Cheers
 
Ying, using a 14.5 amp stator with LEDs and a short or shunt type voltage regulator, is a recipe for burnt out stator. The system will put out way more power than necessary, and is way out of balance. Read and understand Grant Tillers article on voltage regulators. Even Trispark no longer sell the high power stators because of come backs, even using his Mosfett regulator. I am using a 14.5 amp stator with LEDs and an open type regulator from a Harley and no problems. Just finding a place to mount the huge regulator is the worst problem. Graham
 
robs ss said:
Mike, if rubbing between the stator & rotor is the issue surely there would be witness marks on the steel parts to prove that?
It would help to identify if you're chasing a mechanical or electrical problem.
Cheers
Click to expand...
This is the question ☝️


Another question is which stators are failing? Old original Lucas or modern Lucas? 2 or 3 phase?
Is it metal to metal contact, or potting resin expanding and grabbing the rotor?

I just measured an original stator and the ID was 2.96" between pole pairs
A new Lucas 2 phase 16A stator ID is 2.950" between pole pairs
A new Lucas 3 phase 14.5A stator being 3 phase I can't measure across poles, so allowing for the resin being set back I'm guessing it's near 2.95"
 
I will add that I also have all LED lighting, a Tri-spark voltage regulator, and a cNw e-start. The last stator that I installed I went back to a 10.5 A single phase and I've had no issues starting the bike--maybe this is why I finally resolved my stator melting issue? Could I have been overheating the system with the 14.5 A 3 phase stators that were melting?
 
I did a quick calculation on the lighting burden Incandescent lamps Vs LEDs

Riding with dip beam, pilot, tail light and instrument lights on Incandescent = 74Watts, LED = 4.7Watts
That's a difference of 69.3Watts . Assuming battery voltage of 13.8v, the difference in current drawn would be 5Amps.

I would suggest that the 3 phase 14.5Amp stator is more suited to incandescent lamps while the 3 phase 10Amp stator is suited to LEDs
 
I too have had stator rubbing issues albeit very minor but audible but no melting at all although some unsightly cracking but charging is fine.

At Nigel’s recommendation I too had 0.01” machined off the rotor to give 0.02”‘clearance

Just been out and my screeching noise has gone but I’ll be keeping a close eye on things in case it was something else altogether
 
That is what I am trying to find out.The real problem is that I took off a stator that was on my bike for at least 4 years and working fine.It was during a real cold spell and I had a new one in my stash so I thought it was a good idea to put it on and turn the rotor .010 to be thinking I was just doing some winter maintenance.BAD idea.Should have just left well enough alone.Now I am pulling my hair (not much there) out trying to figure out what my problem is.This is one reason I don’t think it is electrical but who knows.
Mike
I have the same set up as HouTex with all LED bulbs,Shoei battery,etc.Due to my electrical ignorance I thought the bigger the charging system, the better.These stators didn’t melt until I had about 100 miles on them. I still am a huge fan of the Shoei batteries and will figure this out soon.
 
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