PMA flywheel runout / balance question

Spot on!
When everything returns from the balancing shop I will do just that.

Plus, I saw a video...
...that shows using a lapping compound to polish off any high spots on the shaft & flywheel.

I'm looking forward to having this all sorted out.
 
Received the flywheels back from balancing...

XS Charge (from a complete kit)
DSCN2446_zps7mvri0i0.jpg


Mike's XS (purchased separately)
DSCN2447_zpswrkz1bvz.jpg


The numbers look like this:
- Stock rotor (electro-magnet); out 0.08 oz-in.
- PMA rotor #1 (XS Charge); out 0.18 oz-in and corrected to 0.03 oz-in.
- PMA rotor #2 (Mike's XS); out 0.24 oz-in and corrected to 0.02 oz-in.

I had told the balancing shop that max RPM would be 8000, and they replied that the "balance tolerance" should be around 0.03 oz-in. at that speed, but that was considered a pretty tight tolerance.

They also said that the runout didn't appear excessive to them, so I am going to test fit the flywheels again, with & without the woodruff key.

For anyone considering getting their flywheel (stock or otherwise) balanced, Jim VerCande at Detroit Balancing Services is easy to work with, and has tooling ready to accept XS650 flywheels.
You can contact Jim at:

Detroit Balancing Services
572 S. Mansfield
Ypsilanti,Michigan, USA, 48197
TEL: 734-480-2337
FAX: 734-480-2354
website : detroitbalancing.com
email : jim@detroitbalancing.com
 
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Good follow up with this story. It does show the poor quality parts coming out of the chinese factories.
Buyers need to be aware of what they are buying.
Mikesxs, XSCharge, TC bros, HHB , all sourcing their parts from Electrosport in California, which is the distributor for Procom Engineering, which has the 2 manufacturing plants in China.
 
retiredgentleman said:
Good follow up with this story. It does show the poor quality parts coming out of the chinese factories.
Buyers need to be aware of what they are buying.
Mikesxs, XSCharge, TC bros, HHB , all sourcing their parts from Electrosport in California, which is the distributor for Procom Engineering, which has the 2 manufacturing plants in China.
Click to expand...

All I will say is German Engineering.
LOL
 
All I will say is you get what you pay for. If your gonna pay fort these cheap Chinese parts, get them rechecked by a liable source and send the vendors a bill for getting true quality control.
 
I agree, the only reason I see the China and Taiwan parts being sold is there is good money to be made. Suppliers could sell better ignitions and parts but there is more money with cheaper ones. A good example is the Powerdynamo ignition, Not because I sell them but because I have not seen a better after market ignition. You can buy direct or other Suppliers could sell them for a modest markup (10-20%) but there is more money in the China and Taiwan parts. I know about the mark up because I just got solicited by 2 Taiwan company that sells many of these parts, there parts list they sent me almost looked like a Mikesxs catalog. Including the performance cam , coils etc. a pretty big list. They showed me the mark up, very nice the Performance cam alone would make a 150% profit. I told them I had to pass. Selling quality parts have what kept me in business. Can't change now.
If anyone wants to get into the Taiwan parts business email me at gary@hoosracing.com and I will forward your information to them . I have there contact information. But you better have big pocket, they want you to buy a lot at one time. Good luck.
 
Amen, Gary. What amazes me is the way some guys who've been burned on known crap rationalize the bad choice and keep going back to the vendor who keeps screwing them. We all know the old proverb: "You can't get something for nothing." Here's the corollary: "It's easy to get nothing for something."
 
What I don't understand is that you can buy the same chinese parts on E-bay, for much less money!
Banshee (chinese knockoff) PMA stator, rotor, and a rec/reg................................about $87.50 on E-bay.
HHB; PMA stator, rotor, and a rec/reg.............................$319.00
Mikesxs; PMA stator, rotor, and a rec/reg..............................$297.00

Banshee (chinese knockoff) PMA stator, rotor, rec/reg, CDI box, ignition coil......................about $187.00 on E-bay
HHB; PMA stator, rotor, rec/reg, CDI box, ignition coil.............................$579.00

Its bad enough that the lads are buying poor quality chinese parts, but they are paying very high prices as well!
Its sad to see the inexperienced lads getting fleeced like this.
 
Am i failing to understand something here................Run out is different to balancing, right?

If the PMA rotor is wobbling, or the an area is close to the Stator as it turns, then it relates to where the Crank shaft goes through the rotor. If the hole is not machined true on the rotor then it will cause the problem you have. That is a manufacturing prob and i have seen a tutorial, (won't say who done it), on how they filed the crank shaft at a spot to make the rotor sit square to the Stator. This was a recommendation so the kit would fit due to bad manufacturing.

I don't see how taking some weight from the out side, to balance, is going to square or fix the run out of the Rotor to the Stator..............???
 
650Skull said:
Am i failing to understand something here................Run out is different to balancing, right?
...I don't see how taking some weight from the out side, to balance, is going to square or fix the run out of the Rotor to the Stator..............???
Click to expand...
Correct. I had checked into getting the rotor trued and it was just too expensive. But the rotor wasn't making contact with anything when mounted on the bike, so by that measure it was still 'good'.
I figured that if I was going to run an out-of-square rotor, I could at least get it balanced so that the vibration factor would be minimized.
Plus, the balancing shop could verify the runout on their equipment, to either validate (or invalidate) the runout I had noticed.
 
grizld1 said:
...We all know the old proverb: "You can't get something for nothing." Here's the corollary: "It's easy to get nothing for something."
Click to expand...
The saying I seem to live my life by is;
"If you have a problem, throw money at it until it goes away."
 
Looking at your two balanced PMA flywheels, it appears that they were similarly off-balance, at the same locations (compared to the woodruff key slots).

Reminds me of what some SBC Chevy hot-rodders ran into when doing flywheel swaps between regular cranks and 400cu-in cranks. Normal V8s being internally balanced, the 400 (as used in the 383 hybrid) being externally balanced.

Just wonderin' if these aftermarket rotors are intentionally off-balanced to comply with a different engine's requirements...
 
TwoManyXS1Bs said:
Looking at your two balanced PMA flywheels, it appears that they were similarly off-balance, at the same locations (compared to the woodruff key slots).

Reminds me of what some SBC Chevy hot-rodders ran into when doing flywheel swaps between regular cranks and 400cu-in cranks. Normal V8s being internally balanced, the 400 (as used in the 383 hybrid) being externally balanced.

Just wonderin' if these aftermarket rotors are intentionally off-balanced to comply with a different engine's requirements...
Click to expand...

So, maybe, the crankshaft and rotor was, or, could or should be balanced as a unit?

Scott
 
TwoManyXS1Bs said:
...Just wonderin' if these aftermarket rotors are intentionally off-balanced to comply with a different engine's requirements...
Click to expand...
That caught my attention, too.
The similar location of the corrections made to the rotors could just be an indication of consistency in the manufacturing process.

I believe these rotors are unique to the XS650 application. They probably start as Banshee rotors, but they get a different size key slot machined in.
Which leads me to believe that the PMA conversions that don't use a woodruff key at all probably use a standard Banshee rotor (no need to match the XS key). This could be a mess, if those rotors are intentionally imbalanced for a Banshee. :shrug:

That's why I had the stock rotor checked. If the aftermarket rotors are intentionally weighted in a specific location (for the 650), then they were 3 times heavier in that location (24 oz/in vs 8 oz/in) than the stock rotor. So even if they were designed to be heavy in one spot, they still got it wrong by being far too heavy.
 
Wait a minute here guys. You're over thinking this.
These are Chinese reproduction rotors made to fit a Banshee or an XS650. They are mass produced in a factory with no quality control and no balancing is done during manufacturing. That's just how it is with a Chinese factory that manufactures these parts to a low price point.
By contrast, my stock Hitachi rotor has holes drilled in the rotor frame, that were made during the balancing step. The Japanese only make things to a high quality standard. Its in their culture..................they don't know how to make low quality parts.

The Chinese have the ability to make high quality parts, but that is only if you pay a high price when you request the production run.
Electrosport (aka Procom Engineering) , which is the supplier to HHB, Mikesxs, TC Bros, XSCharge, etc, obviously pays very little with their orders to the Chinese factories.
 
XSLeo said:
In your first post you say you installed the flywheel with a key. You might try installing it without the key. Perhaps the key is a bit tall and cocking the flywheel...
Leo
Click to expand...
Excuse me while I take off my helmet as a show of respect to XSLeo. The key was indeed the culprit.

Tonight I fit both rotors, with & without the key installed.
WITH the key they both wobbled. A lot.
WITHOUT the key installed both rotors spun dead true. Impressively true.

So we can chalk this whole thread up to mechanic's error. :doh:
But at least we did find -- and fix -- the imbalance, so there was a bit of knowledge shared in that regard.

Sorry for the wild goose chase, gents. I sincerely appreciate all you input and comments. I owe you all an adult beverage of your choice.
But at least now I have no reservations about the stability of this flywheel. And for that I offer you my thanks!
 

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