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Discussion Starter #1
Yet another charging issue post, but with a twist.

Grab the popcorn. It's story time.

The Bike
2007 DL1000. Just purchased. 9,000 miles.

Short story
When installing a new generator rotor, torquing beyond 70ft-lbs freezes the starter drive gear, generator motor, and crankshaft.

Long story (How'd I get here?)
Years ago, I purchased a salvage title 2007 DL1000 with 20k miles on it. It just rolled past 200,000 miles recently (thanks many times to the advice found throughout this very site) and after losing my job during the pandemic, I thought I'd treat myself to something with a little less miles on the odometer to enjoy the summer with. The idea being I could transfer some of the more expensive farkles over, saving coin. A friend found me an identical year bike with an unbelievable 9,000 miles on it. Score!

A few hours to ride it home and I was the proud owner of a shiny, as close to new Strom as I've ever had. The next weekend, I joined some friends for a day ride and about 5 hours from home near the Nevada/California border about an hour south of Lake Tahoe, my gauges suddenly died and engine power was decreasing.


Being a seasoned Strom owner, I'm painfully familiar with the Achilles heel that is the charging system. So, while rolling through the twisty roads, I reached in and unplugged the headlights.


Gauges came back shortly after and I used my borrowed time to try to get to civilization. Almost made it too. Alternating between some dangerous holding of a friend's bike towing maneuvers and good old fashioned hoofing the heavy bike walk of shame, I got the DL to a safe place and hitched a ride home.


My mechanical issues meant an unplanned route home and instead of heading South towards sunny, clear skies, we unknowingly detoured right in to pouring sheets of rain and pummeling hail cycles at just above freezing. Of course we hadn't dressed for this occasion. I may still owe some dinners to the group for this one.


The next day was entirely spent driving back to retrieve my troubled bike and getting it home in a trailer.

Come the next morning, I charged the battery and put a stator and gasket on order right away. Then, ran the usual stator tests. Resistance between all three phases? Same. Path to ground on any of the phases? Nope. Stator voltage with the engine running? 0 VAC, all phases. Well, that's a clue if I've ever had one. Time to crack it open and see just how bad it is.


Pretty bad. Half the magnets survived with minor scarring, but the other half were a mix of chunks and magnetic powder in the oil.

273600


The stator was pretty beat up too. Magnet shrapnel had cut in to the laminations and the windings.

273604


273605


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[Media limit reached, continued in next post]
 

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Discussion Starter #2 (Edited)
I added a new generator rotor to my shopping list and it was in my hands within a week. Unfortunately, a magnet on this new rotor was also cracked, so a second one was ordered and in my hands within a week. I quickly got to JB welding between the magnets on the new rotor, because I know better thanks to y'all.

With so much waiting, I had plenty of time to read up on the surgery, not just from the manual, but from people like @realshelby in threads like this one and this one. I ordered the special 20mm rotor puller tool and everything was as advertised. Torque the tool, tap it with a hammer, repeat until pop goes the rotor. Surprisingly little drama.

The same was true with getting the starter clutch off the back of the rotor. Heat, twist, repeat.


I cleaned up the clutch, removing the magnetic debris and cleaning up the threads. Installation of the clutch on the new rotor was a breeze and all the bolts were torqued to spec. The starter drive gear popped in and ran one way just like it should. The whole assembly slid on to the crankshaft and torqued to 115ft-lbs. Too many things going right you say? That makes the two of us that were suspicious. It was at that point I noticed the starter drive gear would no longer turn. In fact, nothing wanted to. Maybe if I just button it back up and put some oil in it, the sprags on the clutch will just free themselves magically when I started the bike? Yep. I was that desperate. Don't know the answer to that, because the starter couldn't actually turn the bike over. More investigation was needed.


This is where I'm stuck. When I torque the rotor to 40ft-lbs, the starter drive gear is free to operate and work. Same for 60ft-lbs as the rotor draws the assembly closer to the block as it climbs the crankshaft taper. Somewhere at about 70ft-lbs, the starter drive gear will no longer spin and is sandwiched by the rotor.


What's going on?

I chased a few good ideas after noodling the issue over with friends. The calipers I have could do a depth measurement of the crank cavity but not ID, so I did that. Same. Distance between the starter gear and rotor on both rotors? Same. Torque wrench out of spec? Different one has same results.

Looking down the bore of the rotor at the oil marks, it looks like the crankshaft is indeed seating deeper on the new rotor. Could it be the taper on the new rotor is too large? Part numbers on the rotors are identical. They're both OEM. I'd like to make a harbor freight run and get a set of telescoping gauges to not only prove this part is different, but that any replacement isn't before I go JB welding away at it.

273608


Appreciate any insights. I dug around here and on google, but only found one case that was similar to mine that only got me to a dead end.
 

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Discussion Starter #3
I walked in Harbor Freight, went right over to the measurement aisle, and the item I was looking for was not only present, but in ample supply. When does that ever happen?

Got it home and immediately took measurements at the bottom of the bore (end of the taper, the narrowest part).

Old Rotor
273632


New Rotor
273633


I can repeatedly measure a difference of about 0.2mm. Thinking that's enough to matter. Bad part?

I may be crazy, but at least it appears that I'm right.
 

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Discussion Starter #4 (Edited)
Well, got third rotor in the mail just now. Upon zeroing everything, measuring it, and with @IW4 as my witness, it would appear the third time is a charm. The ID measurements are IDENTICAL to my part off the bike to the second decimal place when I measure carefully.

Part off the bike:
273754


Suspected bad part:
273755


New part:
273756


Next steps include JB welding, installation, and vindication. 😁
 

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Looks like you got it. But, that is just bizarre that a new factory part that demands such precision - doesn't. Wow.
 

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Looks like you got it. But, that is just bizarre that a new factory part that demands such precision - doesn't. Wow.
I was there both times he's used those scoping gauges. It's absolutely bonkers that it came to that, but the relief on his face was straight-up palpable.
 

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I wonder if the "too large" rotor was a 2014+ that got mixed up before they installed the magnets. The 2014+ crankshaft taper is larger diameter. I don't know the exact size difference, but .2 mm is a LOT of difference in a taper fit.
 

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I wonder if the "too large" rotor was a 2014+ that got mixed up before they installed the magnets. The 2014+ crankshaft taper is larger diameter. I don't know the exact size difference, but .2 mm is a LOT of difference in a taper fit.
I mean, the model numbers were identitcal. I can't help but think that rotor was cursed to begin with; it's got an awful lot of balancing holes on it.
 

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Discussion Starter #10
Well, I didn't want to call it too early, but I've put some miles on the bike now including a weekend of riding/camping- no issues!

Obviously, the new part fit properly and did not bind the crankshaft up. Heck, the starter motor even turned like it should.

So, I of course JB welded the edges of the magnets before buttoning things up. This, being my third time doing it, I'm getting pretty good at it. Heck, might have to put it on my resume.

274241


Cut up some drinking straws to form the JB weld into a U shape wedge and keep it from crawling up the magnet. Then, just popped them out...


and cleaned up the edges.

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I did the full oil/filter change, then warmed the bike up. Did another filter/oil change, then put 100 miles on it. Did another filter/oil change, and all back to normal. Three oil changes in 24 hours- that's a new record for me!

I had a bit of a scare on the first ride, when I made it 2 miles from home and the engine died. It started, I made it another 2 miles, and it died again. With my electronics knowledge, I had an idea what it might be. The bike wasn't throwing any codes. I got it back the the garage and tested. Started the bike, then unplugged the pickup coil. Engine stalled without any error codes. Bingo! I had put dielectric schmear on the contacts of the stator connections... including the pickup one. That coil is two wires and analog. Any impedance, I'd bet, can degrade that signal significantly.

So, I blasted out the grease with the air compressor and it has run without issue since!

I bought an extra insurance policy in the form of a magnet for the oil filter.

274239


Yes, fighting magnets with magnets! Putting this magnet in the oil circuit has really helped pull a lot of fine magnet particles out of the engine. You can see the silver edge where I wiped my finger vs. the black edges all the way around the rest. Oh, and the magnet on the drain plug was clean- it picked up next to nothing.

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I also installed my Polaris series regulator mod from the old bike and my home made adapter mount.

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Voltage is a very strong 14.7 at idle and stays strong while riding. All the AC phases check out too. Can even see the voltage drop and rise after the battery is charged when the series regulator starts pulsing on and off.

Time to start bolting, taping, gluing, and zip tie...ing, on the other farkles!

Plan on painting the old case frame, new cases, and crash bars. I've to rebuild the scottoiler. Transfer over and upgrade my electrical accessories spaghetti western along with my bike mounted camera systems. The list goes on...
 
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