Replacing ignition system with CDI on Sachs 504

Mason Campbell /

Hey guys, soooo my bikes points took a giant dook. Went in to set my timing today and noticed my points aren't opening at all. No movement no matter what I do. After the headache I said screw it I'm getting a CDI.

Now I've been looking through all the wiki pages I could find and haven't seen anything in regards to installing a CDI on a 504 and on treats all the CDI's I find keep saying either "fits puch.... sachs... blah blah" or just says it's for a 505...

So what do I buy? And can anyone point me into the direction of a how to wiki?

Re: Replacing ignition system with CDI on Sachs 504

The 504 points do that

Just set the gap with the flywheel off and lap that taper

Re: Replacing ignition system with CDI on Sachs 504

Mason Campbell /

> Wesley Ambrosini Wrote:

> -------------------------------------------------------

> The 504 points do that

>

> Just set the gap with the flywheel off and lap that taper

I don't have a puller at the moment. Went and bought a 3 prong jaw and it wouldn't come off. And the center bolt started to get marred. So had to stop that before it got too bad. And as far as I could see, there was only a single screw I could access to adjust the points. When I loosened the screw the whole point assembly started to come loose, not just the top part to adjust it. Every tutorial video I have watched shows a adjustment screw. And I'm not seeing anything but this single screw right next to the points.

Any idea what CDI would fit a 504?

Re: Replacing ignition system with CDI on Sachs 504

That is the adjustment screw

If you can't even get the flywheel off how were you going to put on a cdi?

I'll take some photos tomorrow and try and help you out. Buy a flywheel puller from treatland if you own a moped it's a must have

Re: Replacing ignition system with CDI on Sachs 504

Mason Campbell /

> Wesley Ambrosini Wrote:

> -------------------------------------------------------

> That is the adjustment screw

>

> If you can't even get the flywheel off how were you going to put on a

> cdi?

>

> I'll take some photos tomorrow and try and help you out. Buy a flywheel

> puller from treatland if you own a moped it's a must have

Well I was gonna order the puller with the CDI. And when I loosen that adjustment screw and place a .014” feeler gauge in there, then tighten the screw back up the points still don’t open no matter the position of my piston

Re: Replacing ignition system with CDI on Sachs 504

Sorry I don't know your skill level and I just assumed you were super new.

I had the same problem, when you tighten the screw it turns the points closed if that makes sense. I had to take the flywheel off mine to get them to gap right.

As far as the cdi, I don't know if they make one for the 504. The 505 shares a taper (mostly) with Puch and the derbi motoplat (pretty sure) but 504 doesn't have a lot of performance parts

Re: Replacing ignition system with CDI on Sachs 504

Mason Campbell /

> Wesley Ambrosini Wrote:

> -------------------------------------------------------

> Sorry I don't know your skill level and I just assumed you were super

> new.

>

> I had the same problem, when you tighten the screw it turns the points

> closed if that makes sense. I had to take the flywheel off mine to get

> them to gap right.

>

> As far as the cdi, I don't know if they make one for the 504. The 505

> shares a taper (mostly) with Puch and the derbi motoplat (pretty sure)

> but 504 doesn't have a lot of performance parts

No worries man! I appreciate the help all the same.

Yea that’s what I’ve been noticing when shopping around. It’s my first Sachs engine. I primarily have experience with Mobys. I can’t find anything about it on the wikis. But if you have time if love to see some pictures of the adjustment screw to make sure I’m doing it correctly. Cause with the flywheel on I can’t get the points to keep the gap I wanna set. Just closes right up every time.

Re: Replacing ignition system with CDI on Sachs 504

I forgot how shit this is to do on a 504

So the problem is that at TDC the window isn't open enough to allow my screwdrivers into the slots

I kinda fix this by setting the point gap at the fire mark (the 'M' on the flywheel) instead of TDC. Instead of a .016" feeler I used a .013" piece of card stock. After I set the gap to .013" at the fire mark it was at .016" at TDC. This may require some trial and error.

I just did it 3 times in a row and the result was pretty reliable each time.

The 'O' and arrow on the flywheel is TDC when lined up with the mark on the case. My screwdriver is pointing right at the case mark in this photo

TDC.jpg

loosen the points adjustment screw

adjustscrewdribver.jpg

put your feeler gauge into the gap

paperinthegap.jpg

(edited)

Re: Replacing ignition system with CDI on Sachs 504

lightly press the points onto the lob with a screwdriver in this spot

holdingpoints.jpg

all together it should look like this

Slotsminusflywheel.jpg

tighten the adjustment screw

that is it mostly.

I had to take the stator out and hog out the slots to get it to about 18* BTDC with is OK, not ideal

Also I was totally wrong, you cannot do this with the flywheel off like a puch (edited)

Re: Replacing ignition system with CDI on Sachs 504

Mason Campbell /

Dude this is awesome thank you so much. I’ll see if I can get that pulled soon and take a swing at it myself

Re: Replacing ignition system with CDI on Sachs 504

You can't do it with the flywheel off, my bad. I did the pictures with it off so you could actually see what's happening

Re: Replacing ignition system with CDI on Sachs 504

Mason Campbell /

> Wesley Ambrosini Wrote:

> -------------------------------------------------------

> You can't do it with the flywheel off, my bad. I did the pictures with

> it off so you could actually see what's happening

Can I set the points with the flywheel off? And then set the timing with the flywheel on? Just want to be sure

Re: Replacing ignition system with CDI on Sachs 504

> Mason Campbell Wrote:

> -------------------------------------------------------

> > Wesley Ambrosini Wrote:

>

> > -------------------------------------------------------

>

> > You can't do it with the flywheel off, my bad. I did the pictures with

>

> > it off so you could actually see what's happening

>

> Can I set the points with the flywheel off? And then set the timing with

> the flywheel on? Just want to be sure

You need the flywheel on to set the gap because the points have to be set while on the lobe, if that makes sense.

You can set the timing with the wheel off, but you still have to check it with it on so there isn't a need really.

Re: Replacing ignition system with CDI on Sachs 504

Mason Campbell /

Gotcha. I’ll take a picture of mine Here soon. My points are set slightly different to yours. Mine are horizontal while yours seem to be vertical in position to the rest of the assembly

Re: Replacing ignition system with CDI on Sachs 504

Mason Campbell /

Here’s my points. They seem situated differently then yours

C9874D63-90B7-41EC-828E-72AF28398D46.jpeg

Re: Replacing ignition system with CDI on Sachs 504

The principles are the same.

Either way it should be easy / cheap to get a used set off of buy+sell if yours are goofed

Re: Replacing ignition system with CDI on Sachs 504

Mason Campbell /

Sweet, seriously man I really appreciate the help. Thanks for taking the time to take those pictures. Hopefully my points are muffed and I can get this thing back running right.

Re: Replacing ignition system with CDI on Sachs 504

Um, you're really going to have to take that flywheel off. It's probably on a tapered shaft with a key. See if you can find a bike or lawnmower mechanic who will talk to you, or someone who is very old at a hardware store or tool store, and discuss pullers and flywheel removal.

Sometimes you can simply loosen the nut on the shaft, place a block of hardwood atop the nut, and give the wood block a sound whack to disengage the tapered shaft from the flywheel. Aside from that, an ignition module isn't difficult to install: you remove the points and condenser to give yourself some room, install the tiny thing anywhere that's handy, and connect the wires. These modules will work on any engine with a single-magnet flywheel magneto, which yours very likely is.

When you replace the flywheel, make sure that the key is in good shape and do _not_ put anti-seize compound on the taper, for doing so will reduce the friction needed on that taper and the rotation of the flywheel on the shaft will shear the key right in half. Just clean up the mating surfaces nicely, line up the key with the keyway, and thunk the flywheel onto the shaft. Tighten the nut securely and you're done.

It is also possible that the flywheel is meant to be pulled by threading bolts into threaded holes supplied on the flywheel itself. There would likely be two or possibly three of these, and what you'd do is thread some sturdy metric bolts into these holes and, paying close attention to what they'd screw into inside the magneto case, tighten them one after the other until they force the flywheel off. If there are threaded holes in your flywheel, generally close to the hub (but not always) that may be how you're supposed to remove the flywheel.

I have to do precisely this same operation on my new old 1984 Trac Clipper but I'm waiting for the weather to warm up a bit.

Re: Replacing ignition system with CDI on Sachs 504

Looks like the end of that shaft needs a bit of love .

If you don't have a hub puller , check the holes along side the access windows of the flywheel . They may be threaded . If so , try using a steering wheel puller .

Re: Replacing ignition system with CDI on Sachs 504

Mason Campbell /

> Mark Kinsler Wrote:

> -------------------------------------------------------

> Um, you're really going to have to take that flywheel off. It's

> probably on a tapered shaft with a key. See if you can find a bike or

> lawnmower mechanic who will talk to you, or someone who is very old at a

> hardware store or tool store, and discuss pullers and flywheel removal.

>

> Sometimes you can simply loosen the nut on the shaft, place a block of

> hardwood atop the nut, and give the wood block a sound whack to

> disengage the tapered shaft from the flywheel. Aside from that, an

> ignition module isn't difficult to install: you remove the points and

> condenser to give yourself some room, install the tiny thing anywhere

> that's handy, and connect the wires. These modules will work on any

> engine with a single-magnet flywheel magneto, which yours very likely

> is.

>

> When you replace the flywheel, make sure that the key is in good shape

> and do _not_ put anti-seize compound on the taper, for doing so will

> reduce the friction needed on that taper and the rotation of the

> flywheel on the shaft will shear the key right in half. Just clean up

> the mating surfaces nicely, line up the key with the keyway, and thunk

> the flywheel onto the shaft. Tighten the nut securely and you're done.

>

> It is also possible that the flywheel is meant to be pulled by threading

> bolts into threaded holes supplied on the flywheel itself. There would

> likely be two or possibly three of these, and what you'd do is thread

> some sturdy metric bolts into these holes and, paying close attention to

> what they'd screw into inside the magneto case, tighten them one after

> the other until they force the flywheel off. If there are threaded

> holes in your flywheel, generally close to the hub (but not always) that

> may be how you're supposed to remove the flywheel.

>

> I have to do precisely this same operation on my new old 1984 Trac

> Clipper but I'm waiting for the weather to warm up a bit.

Awesome! And yea I’m order a flywheel puller from treats. The flywheel has threads in the center of the hub. I tried using a 3 pronged puller I have. And surprisingly the flywheel wouldn’t budge. I have to re thread the center shaft a tiny bit cause it marred the end instead of popping the flywheel off.

Do you have any recommendations for CDIs? Everywhere I’m looking they seem to be specified for the Sachs 505, or are way to general to trust. I might just email treats and ask them.

Re: Replacing ignition system with CDI on Sachs 504

Dirty30 Dillon /

Not to undermine Mark, but you have a 4 magnet system. The single magnet system he is discussing is typically used on lawn equipment, like tractors/etc. It will not function on this bike.

AFAIK, there is no full stator replacement for the 504. I think there maybe is/was a pietcard coil for this.

Also, it's all kind of moot because your crank is roasted. Your best best is to pull the flywheel and repair the threads as best you can. You may find yourself buying a spare parts motor anyways.

Re: Replacing ignition system with CDI on Sachs 504

Mason Campbell /

> Dirty30 Dillon Wrote:

> -------------------------------------------------------

> Not to undermine Mark, but you have a 4 magnet system. The single magnet

> system he is discussing is typically used on lawn equipment, like

> tractors/etc. It will not function on this bike.

>

> AFAIK, there is no full stator replacement for the 504. I think there

> maybe is/was a pietcard coil for this.

>

> Also, it's all kind of moot because your crank is roasted. Your best

> best is to pull the flywheel and repair the threads as best you can. You

> may find yourself buying a spare parts motor anyways.

Gotcha, and the threads look worse in the picture then in person. After removing the flywheel a thread chaser should have no problem getting it back on track. And I wish there was a CDI made for the 504. Oh well. Hopefully this assembly isn't roasted and I can get it tuned up. If not... guess I'll have to buy a new one if I can find it.

Re: Replacing ignition system with CDI on Sachs 504

There's a CDI that is made for the 504 from HPI:

I use it on my Sachs 504. They list it for the Sachs 504/2, but beside the gearbox, the engine is exactly the same as the 504/1. They list for the 504/1 the Kit 210K299, but that one has a larger stator plate, which only fits the 505. I don't know why they have such missinformation on their website.

Re: Replacing ignition system with CDI on Sachs 504

Sorry link got lost:

HPI

Re: Replacing ignition system with CDI on Sachs 504

Mason Campbell /

I emailed treats directly and they hooked me up with the correct stator size and flywheel. All came in yesterday. Fixed all my problems!

Re: Replacing ignition system with CDI on Sachs 504

Which one did they hook you up with? I have a 504 as well and ha ent had to go at the points yet, but I'm sure I will and the info will be good to have.

Re: Replacing ignition system with CDI on Sachs 504

Fix the end of the crankshaft first. As long as there are several threads left on the crank just outside the flywheel, seated as it is, it will be fine. Use files and take your time. Avoid pullers with arms for most all vintage mopeds. I know several brands pretty well and all use center thread-in pullers. Too much risk of messing up flywheels using arms and bolt pullers. Once you have the flywheel off, figure out with how the points are mounted and operate as if you we're trying to gap them so you know how they work. Adjusting means loosening the screw just enough to use a slotted screwdriver to open/close the gap in tiny amounts. Loosen does not mean backing the screw out a lot. I'd also recommend that you move your condenser out from under the flywheel while you're in there. It's just a matter of time before it dies. Great instructions on the wiki

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