PMA flywheel runout / balance question

CaptDan

CaptDan

1980 XS650 SG
Messages
19
Reaction score
2
Points
3
Gentlemen,
While checking the installation of a new Banshee-type flywheel (an XS Charge unit with a Woodruff key), I noticed that it had a noticeable amount of runout when the motor was turned over -- both axially and radially. Total movement is about 1-2 mm measured at the outer edge of the flywheel. I could also see that the gap between the flywheel & stator coils would vary as the crank rotated.
Nothing is touching or getting too close (as far as I could tell), but it made me wonder how much 'wobble' is permissible with these flywheels.
Will the wobble cause vibration?
Are the flywheels balanced?
Has anyone else noticed something similar?

The flywheel was carefully installed and torqued. (And fussed with & rechecked.)
The crank appears straight.

Any input would be welcome.
 
Thanks for the input, TooMany.

I had checked that thread, but these PMA flywheels are a different beast, and I have a feeling that the tolerances I'm seeing may be considered acceptable by the manufacturer (made in China?).

Like you, the wobble just doesn't look right to me. I'll pull the flywheel off and give it another go...
 
All of the aftermarket PMAs, that are made in China, are poor quality and what you are seeing is likely typical.
Balancing.................I doubt it. Quality check on runout at the factory..................I doubt it.
You have to realize you are buying Chinese quality (or lack there of) not Japanese quality.
 
Yes, this is what I'm thinking, retiredgentleman.

I'm still hoping to hear from people who have installed one of these to tell their thoughts;

- Is the excessive runout not an issue, or is it a nagging concern?
- Are there added vibes or is there no noticeable difference?
- Or, has no one received a flywheel that appeared out-of-round?
 
Yes, surely some other XS Charge buyers would be able to advise you of their experience. Sad to say but buying these chinese aftermarket PMA components tend to give problems.
Why don't you use the stock type alternator......................did your bike come with one?
If you're determined to use a PMA, then its best to only use Japanese components.
 
The stock system crapped out, so I'm switching to a PMA so that I can run the bike without a battery.
A KZ500 stator, FZ1000 regulator, and capacitor are installed & wired up. The only piece missing was a flywheel.

I guess the only way to get an OEM-quality flywheel would be to get an actual Banshee unit, unless someone knows of a non-China source.

Thanks!
 
Hey capt dan,
I'm actually having a very similar issue that some of the guys are helping me trouble shoot at the moment. I have a mikes PMA and it doesn't seem to run true at all.
Same as yourself I was pretty pedantic about the install and I'm hoping that it's not a bent crank that's making it wobble.
I have an odd rubbing noise coming from that area which alerted me to the problem.
I'm waiting for a puller to turn up in the mail at the moment to have a better look but I would be interested to know how you got on with yours.
Cheers.
 
Get a PMA from MZB, or a complete PMA/CDI setup from them. The even have a system for 277 degree replaced engines.
Why do people waste their money on Chinese CRAP, when they can get a German designed system, with components made in Germany and Czech Republic?
I have a MZB PMA/CDI on my -74 RD350, and it has worked great for 2 years now. I haven't even changed a spark plug. On a 2 stroke.......
 
Retired it's similar but they make them for the XS650 ,no machining needed everything is in the box. I been selling these for over 10yearsYou and others gave me a hard time, last time I posted something about these, said all I wanted to do is sell parts. Yes I do, good parts not junk. Nothing better out there. www.hoosracing.com
the company has been in business for over 19 year. Gary
 
call it tough love hooser. looks like a good product.
since you came back without your nickers in a twist, I shall let thee pass.lol
 
Oh Great one, my thanks! If any racer out there I have a new race ignition, Penton racing stopped selling ignition I found a great replacement. gary@hoosracing.com for details.
 
do you have a electronic ign for a 1972 Honda xl 250? similar to the pamco? pm me if you do
 
Yes you are correct, you can buy just the charging system, as far as the professional look they are not quality, I been using for over 10 years, race with one , very reliable. No more messing around with timing at your cam. set and forget.
 
I bolted on another XS Charge flywheel (one from a complete kit), and the runout was noticeably less, even though by all appearances the two flywheels are identical.

I hope to get a dial indicator soon so I can get real readings for comparison.
I also may check to see if any shops around here can true & balance a motorcycle flywheel.
 
Update;
I checked with a machine shop about correcting the runout on these two aftermarket flywheels. I was told it would cost more to true them than what they are worth.

I emailed Hugh's Handbuilts to see if they have any experience/feedback/thoughts on the runout/balance of these aftermarket flywheels, but have yet to hear back.

So since truing them is cost-prohibited, I've sent them out to be balanced as a 'second-best' solution.
I also sent along the stock rotor to be checked, so that its numbers could serve as a baseline.
I hope to have more info soon.
 
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.
If it runs true or better with no key, try grinding a bit off the edge and reinstall with this shortened key.
Leo
 

Similar threads

muskallunge
PMA Banshee Swap Help
Replies
10
Views
3K
muskallunge
muskallunge
da evil one
Anybody know if you need woodruff with Hughs PMA flywheel?
Replies
12
Views
3K
toglhot
toglhot
Back
Top