PMA Install Questions

[Machi]

Setting up a Hugh's PMA kit on a '75 rebuild. Going to be running without starter or battery, with stock dual points. Have a TCBros capacitor. Simplified wiring, with only headlight, taillight, brake light, ignition switch, headlight switch.

With the right side already buttoned down - What's the safest way to hold the crankshaft steady while tightening down the PMA flywheel?

Is the position of the flywheel relative to the crank NOT important, as long as we get it at TDC before marking it?

Thanks - I'm sure I'll have more questions (like setting up the old dual coils!)

 

[TwoManyXS1Bs]

Hi, Machi. With any type of shaft/nut retention system (flywheel, clutch, sprocket, alt pulley, ...etc), I've had best experience with pneumatics, set for appropriate torque.

An issue I've not seen addressed here is phasing of the PMA magnets with the ignition system. Not really an issue with battery systems, possibly an issue with capacitor systems, a real issue with batteryless PMA driven ignition systems.

We used to do this batteryless conversion on select Honda models, and had to phase the flywheel to the ignition, preferably at full advance.

Hoping others will chime in on this...

 

[XSLeo]

I can't say much about Honda's but on the XS650 with points there is no connection between the alternator and ignition.
On the XS650 the taper on the outside of the crank and the inside of the flywheel holds the flywheel enough to prevent slippage. The key is to hold the flywheel in time with the crank, so the timing marks line up.
On a PMA you can run with out a key but anytime you have ignition timing issues you will need to check and possibly remark the timing marks.
Using a key is a good idea. Some PMA rotors use a different thickness of key than the stock rotor. You can grind a key to fit both the crank and PMA rotor. I think the XS Charge PMA rotors are new manufacture and are made with a keyway that matches the keyway of the crank.
As far as holding the crank from turning, put the bike in gear and have a helper hold the rear brake to prevent the engine from turning.
Leo

 

[Machi]

Thanks - Sorry I'm still confused. The crank moved on us AFTER installing the new plate and stator, so I don't think I can do a 'light re-install' of the old rotor to find TDC.

Hugh's guide says to discard the woodruff key, but I see now that it can be adapted and kept. http://hughshandbuilt.blogspot.com/2012/03/how-to-install-your-hughs-handbuilt-pma.html

So I need to get the engine (back) at TDC before mounting the flywheel. Perhaps you can point me to a thread with the best instructions for that. Is it sufficient to just observe the left piston, or what else should be taken into account.

And the new flywheel doesn't come with a set mark on it, you have to find that and mark it yourself.

I wrote back to Hugh about all this but he seems to be very busy.

 

[Machi]

I finally solved my confusion (I hope). On the newer Hugh's PMA kits the keyway for the woodruff key on the fly wheel is actually the same size as the keyway on the shaft - you don't need to file the key down to two different thicknesses to make it fit.
This is apparently a recent modification that is not mentioned in his PMA install guide.
Simplifies things a bit if you decide you want to keep that key, which I did.
It was still a b* to line up however.
So the PMA is on. Tomorrow I'll finish the basic wiring and mount the carbs, and might even get this thing started.

 

[wherearewe]

I finally solved my confusion (I hope). On the newer Hugh's PMA kits the keyway for the woodruff key on the fly wheel is actually the same size as the keyway on the shaft - you don't need to file the key down to two different thicknesses to make it fit.
This is apparently a recent modification that is not mentioned in his PMA install guide.
Simplifies things a bit if you decide you want to keep that key, which I did.
It was still a b* to line up however.
So the PMA is on. Tomorrow I'll finish the basic wiring and mount the carbs, and might even get this thing started.

I asked Hugh this exact question the other day. So you simply used the existing woodruff key as is? (I'm waiting on his stator and rotor in the mail).

 

[Gordon]

Now as I see it, your not going to be able to have a timing mark on the flywheel, unless you make one one both the rotor and a stationary one to be a pointer. Not really a hard job to do, but more on that later.
All you need to do is bolt on the kit as Hugh described. It is the simplist charging system ever developed. It goes back to the very beginning of charging system's. The generator's in the Hoover Dam are, or were, of the permanent magnet type. You don't have to worry about the timing now because, as Leo stated, the spark system and charging system are not related to each other. The only connection between them is the battery, or, in your case, the capacitor. Don't try to make it complicated, just follow Hugh's instruction's.
Now, as far as using it for timing, you will have to find top dead center on either cylinder. Easy enough, if the piston is up and the valves are closed, this is TDC. Now, you can put a mark anywhere that is readily accessable. You will have to put a mark on the flywheel and one on the engine, and at TDC, they should line up.
Not so bad, huh? As a new person to building a machine like this, it is easy to get confused, esp. if we start using word's you have never heard of. You did the right thing by asking, and stating what your confusion was about. There is not one person here who did not go through what you are. Some of us did it along time ago, and some, like you, are just starting out.

 

[Machi]

WHERE - So what did Hugh say? I sent him some other questions and got only a partial reply. Maybe Punskalar will chime in here.
As I said it was tricky to line up the keyways. Here's my tip for getting it right, for what its worth.
After several failed attempts, I placed the key on the shaft with a bit of thread lock, and a slight slope down towards the outside, and let it dry over night. Then I carefully filed the inside end of the fly wheel keyway sides and bottom so it would be less likely to catch an edge of the key. Then get LOTS of light down there as you slide it on.

GORDON - I wish you had responded sooner! I was scratching my bald spot bigger and then realized that the question I was asking (about the connection of the alternator to the points ignition) was too dumb for folks to think I was actually asking it! Leo (as always) was a big help. Getting TDC doesn't worry me - the confusion was at what point to do it.

 

[Gordon]

The engine is already running right? OK, the only time you will even have to think about timing is when doing a major tune-up. Replacing the point's is when all that will come into play. Also, maybe if you start having running problems, like sputtering or something, and when work is performed in the point area. Thats when you will need some sort of a referance to be able to actually 'see' where the ignition is actually firing, and if the advance is working properly.

 

[Machi]

Just finished rebuilding the engine - getting close to the first start up. So your tips for setting up the points and wiring are welcome.
I just got the rebuilt carbs and need to install them, finish up the button down, and a few other details.
Our rebuild thread: http://www.xs650.com/forum/showthread.php?t=23837

 

[TwoManyXS1Bs]

Machi, sorry to have added that confusion sideline about alternator phasing. Don't worry, you're doin' fine. Was just prodding to see if anyone was familiar its implications. Guess I may start a separate thread on that later...

 

[Machi]

Actually, that post helped my thinking - er - confusion.

 

[wherearewe]

WHERE - So what did Hugh say? I sent him some other questions and got only a partial reply. Maybe Punskalar will chime in here.
As I said it was tricky to line up the keyways. Here's my tip for getting it right, for what its worth.
After several failed attempts, I placed the key on the shaft with a bit of thread lock, and a slight slope down towards the outside, and let it dry over night. Then I carefully filed the inside end of the fly wheel keyway sides and bottom so it would be less likely to catch an edge of the key. Then get LOTS of light down there as you slide it on.

Not heard back but he usually replies, just takes a few days. Thanks for the tip.

 

[Machi]

I PM'd Punkskalar to ask him to comment here

 

[Punkskalar]

The woodruff key is not needed. On the OEM system, the key keeps the OEM charging rotor in place and keeps timing proper.

The Tapered crank and Flywheel fit are what keeps the rotor from slipping, just as used in some machinery without any mechanical fasteners. When the tapers are properly cleaned, free of grease/oil/rust, then the recommended torque on the crank nut is plenty to hold the PMA rotor in place.

So why not use a Key? Simple, Ive seen more botched installs from bad fitting keys or poor alignment during install, and it's not really needed, so we don't bother with it.

We've sold thousands of our PMA systems, and had about 15-20 botched installs in all these years, so I'm gonna say "Ditch the key and follow the instructions"

Hugh

 

[Machi]

Thanks for completing this thread. This original key (1975) fit both keyways nice and snug. The major danger is knocking it off during install without realizing it and then having it rattling around in there!

 

[xs650guy]

Hey Guys i have a mikes xs pma and ive been searching for PROPER ways to set the timing. my install instructions say to set TDC exactly in the centre notch of the inspection cover while the Hughs instructions show TDC to be approx 1/2" right of the notch. im confused as the kits look very similar. I'm having problems with idle and rough running. i am running pamco and high output coil as well. jetting good, cams set valves good so on so on. but basically i feel the timing is retarded slightly. Does anyone have any ideas???
thanks
robert

 

[kazoom]

your timming mark can be where ever u want on the rotor the important thing is to have the engine at tdc when u mark it..when thats done u can advance and retard the ignition a little with the pick up.
sry 4 my english hope u understand

 

[XSLeo]

If you got the PMA from Mike's use Mike's instructions.
Our wait till Hugh reads this thread and steps in to explain it.
Or wait for Mike's the read this thread and step in. Ha Ha I made a Funny.
Leo

 

[Machi]

Just to add to Kazoom's post - "when you mark it" = when you put the mark on the rotor in line with the TDC mark on the case (or on the sticker - if you have Hugh's).
I just did that on mine finally on Monday. Also made sure that both cam lobes on the left side are on top by opening the valve adjustment covers and checking which ones are tight. Now I need to finish the basic wiring, hook up some gas and see if this thing is going to want to start. Hard to find time between work and getting the garden started.