Switching from CDI to stock stator setup

I got a moped 1.5 months back, been enjoying it quite a bit but it's not running as nicely as it should. The previous owner put a CDI kit on, I think it's worn out and has something to do with the mediocre performance. I want to switch back to a points set-up, but haven't seen anything online for switching from CDI to points, and I don't have any background with this kind of stuff. Is their any documentation / tutorial on switching from CDI to points? Do I just take off the CDI stator and magneto and put the points stator/magneto on and i'm good to go?

Re: Switching from CDI to stock stator setup

Lol worn out on a system with no moving parts? You're kidding right?

Re: Switching from CDI to stock stator setup

Bill Clinten /

i'm talking about a failed part/coil/something not literally worn out... thanks for the productive feedback though

Re: Switching from CDI to stock stator setup

DrGeorgeTompson (Alan) /

> Bill Clinten Wrote:

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

> i'm talking about a failed part/coil/something not literally worn out...

> thanks for the productive feedback though

Idk, when a part of a CDI fails, the whole system usually shits the bed; It doesn't just get slightly worse than it was.

Make sure it's timed right, then fix your jetting. (edited)

Re: Switching from CDI to stock stator setup

Probably not timed right and bike not tuned as stated above.

Assuming this is a Puch, but basically for most mopeds:

You will have to remove the CDI box, (in some cases the box is connected to the HT coil so you will have to remove/replace that as well,) the complete CDI stator with coils (disconnecting all the wiring from your harness), and the CDI magneto.

Then you can put on the points stator plate w/ coils, and consult a wiring diagram to figure out which wire goes where in your wiring harness. Then the the points magneto (don't forget the woodruff key if you're going back to stock) and maybe the HT coil.

Re: Switching from CDI to stock stator setup

Bill Clinten /

Ok so I guess i'm just gonna try to get the timing right for now and see if that helps. Is timing CDI the same for ZA50 and E50, i have a ZA50? Is 2mm generally the right timing? Also - any way to time CDI w/o a timing light (wiki explains timing light method) I'd like to not buy a timing light if possible since i'll probably use it like 2-3 times ever

Re: Switching from CDI to stock stator setup

They turn in opposite directions.

Re: Switching from CDI to stock stator setup

Charles McCusker /

2mm is a suggested starting point, assuming you understand timing. timing light is nice because you can't always trust that the timing marks on the stator vs the flywheel are accurate so it's always good to check them yourself. za50 turns in counter clockwise at the flywheel. what CDI do you have?

Re: Switching from CDI to stock stator setup

DrGeorgeTompson (Alan) /

can you still rent timing lights for free from autozone and advance auto?

Re: Switching from CDI to stock stator setup

Bill Clinten /

I checked with Autozone, they rent a ton of tools for free but no timing light unfortunately. I have no clue what CDI I have, it was on the bike when I bought it, I attached a pic of the magneto, not sure if that helps at all, it looks like the same magneto they sell on treats but idk if that means anything. So you can do the timing the same way you'd time Bosch Stator/points, just set the timing differently (2mm instead of 17)?

IMG_0344 (1).JPG

Re: Switching from CDI to stock stator setup

Charles McCusker /

> Bill Clinten Wrote:

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

> I checked with Autozone, they rent a ton of tools for free but no timing

> light unfortunately. I have no clue what CDI I have, it was on the bike

> when I bought it, I attached a pic of the magneto, not sure if that

> helps at all, it looks like the same magneto they sell on treats but idk

> if that means anything. So you can do the timing the same way you'd time

> Bosch Stator/points, just set the timing differently (2mm instead of

> 17)?

Sorry I'd had a few beers lastnight. 2mm is the position of the piston btdc that you start with for timing. start by reading this https://www.mopedarmy.com/wiki/Ignition_timing_for_CDI

Re: Switching from CDI to stock stator setup

OMG u want to extensively mod a bike but not willing to Shell out $35 for a decent timing light ? Is that the way u figure things out on say a car? Mopeds need about $200 in tools to do them justice.

Re: Switching from CDI to stock stator setup

Bill Clinten /

I have no interest in extensively modding my bike - it came with CDI and i just want it to run right - also i'd be willing to buy a timing light but if there are other ways i want to know cause the bike was $450 i'm not looking to spend 100's of dollars in tools (if i can avoid it). But if a timing light is what i need i found one on craigslist for $5. appreciate all the help

Re: Switching from CDI to stock stator setup

A decent timing.light will perhaps show you that the cdi intermittently is discharging. I've found that with a battery powered inductive timing light such as what.autozone , o reilleys etc a cdi that is intermittently firing will be determined.

Re: Switching from CDI to stock stator setup

No shit, those CDI's do wear out. the pickup stops picking up and they start limiting or just getting slower and slower. I dunno why/how, but they're really shitty CDI's. I'd guess it's just missing more and more often, but it's high enough rpm that you're not hearing it miss really, you just lose a growing percentage of your power.

I've had a few - some were busted within a few hundred miles, all needed some parts replaced, whatever it was - coils, pickups, light coils etc. usually the box was the first to need replacing. Longest one was I had one I kept piecing together from other ones when parts would fail until it finally was a solid working set, lasted 5 years.

but after 5 years it did die, points aint gonna shit out after 5 yrs and this is the best of those CDIs out of probably 10 or more. pickup had died, but with a new pickup it regained like +5mph.

Venkat had one on his magnum, at one point it just kept getting slower, like way slower - new pickup restored it

Not syain it's always the pickup, but that's been in my experience a cause for gradual decline in the performance from those shit CDI's.

I got a new one on my sachs now, runs great but I'm still gonna swap it to points cuz I don't trust it. shitty CDI is shitty.

Re: Switching from CDI to stock stator setup

All that said, I'd still be willing to guess your issue is instead timing and/or jetting. your confusion between 17 and 2mm is frustrating, not your faul, frustrating that it causes so much confusion. mm BTDC is how many mm the piston is Before reaching Top Dead Center. So you measure down the piston hole, find where the top is, turn the crank (via the flywheel) in the reverse of it's running direction (cuz you wanna be before TDC) until the piston moves down EXACTLY 2mm. timing can't be reproducible if you're at "like 2mm-ish"

That's where you want it to fire. (that is if you're setting to 2mm BTDC) - you'd make a mark on the flywheel and the case that line up at that point. You then will NEED a timing light to set timing on a CDI. it's not 100% necessary with points, but impossible without a timing light on CDI. hook it up, turn the bike over, it should be sparking (flashes the strobe) where those marks line up.

on the other hand 17 is DEGREES. if the full rotation of the crank is 360 degrees, you turn the flywheel backwards 17 degrees from tp dead center. you're measuring crank rotation instead of piston height. they're inherently mathematically related, just different ways of measuring the same thing. this explains some of your confusion but holy shit, timining to 17mm piston height would fuck you up! Some further confusion exists because some flywheels are exactly a 360mm circumference - so you can reliably measure distance on the circumference and translate directly to DEGREES. but THIS IS NOT mm BTDC and cannot be confused. mm of flywheel circumference ONLY works if your flywheel is exactly 360mm and you're timing to a set DEGREES BTDC

Re: Switching from CDI to stock stator setup

Finally, switching to points, you will need a flywheel puller, so chock that onto your tool list that you don't wanna build (or you can hammer it off with a rubber mallet, haven't heard that in a while but it can work) and you'll need a strap wrench or piston stop (or some rope/bungee cord in the plug hole - careful not to catch it in the ports...)

you'll need those just to get the flywheels on or off.

then should be as easy as swapping the points stator, attaching the points flywheel. You'll still need to set timing, with points you can time by setting where the points juuuuust begin to open, without needing a timing light. you'll also need a points HT coil, your current CDI likely has an integrated CDI box and coil, so you need a standalone coil.

Then hook lights up to lights, kill to kill. rock & roll.

If you buy a used ignition points set, it'll probably need the points cleaned, may need new points or cam follower or other parts. if you buy a new one, you can get the ones with an internal HT coil, so you just hook it straight up to the plug book and good to go, but those are about as unreliable as the cheapo CDIs anyway...

Pro tip: Swap the lighting coil from your old CDI to the new points stator to keep powerful 12v lights- hot!

Re: Switching from CDI to stock stator setup

Bill Clinten /

Damn now I don't know if I should check the timing, pickup, or just go back to points. Shockingly I already have a piston stop and flywheel puller... I'm pretty sure the jetting is more or less correct, when I got the ped it had an 82, i put in a 70-something, then went down to mid-60's, then up to 70 but it 4-stroked so i was gonna go back down to 68. Pickups look relatively cheap so I might start with a new pickup / checking the timing and if that doesn't work go the points route. Hopefully this $5 timing light works.

Re: Switching from CDI to stock stator setup

Run it on the stand and see if the timing light skips. The ones that don't have a separate energy source (battery) don't work.as.well.at least for me.

Re: Switching from CDI to stock stator setup

> Born to be WillD Wrote:

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

> No shit, those CDI's do wear out. the pickup stops picking up and they

> start limiting or just getting slower and slower. I dunno why/how, but

> they're really shitty CDI's. I'd guess it's just missing more and more

> often, but it's high enough rpm that you're not hearing it miss really,

> you just lose a growing percentage of your power.

This has happened to me multiple times. Still fires and seems to run fine, but does weird things at higher rpm. It was always the pickup that needed to be replaced.

Re: Switching from CDI to stock stator setup

Bill Clinten /

So I finally got a timing light - the timing was definitely way off, like ~25mm bTDC, the stator plate didn't have enough room to adjust the timing enough so I dremeled out the slot where the adjusting screws go. Unfortunately i'm a bozo and I nicked the white wire coming from the pickup (timing pulse wire).

Now, although I got the timing significantly better, the bike won't idle or even start unless I rev it up immediately and keep on the throttle.

I was searching treats and googling it but I can't find where to get the replacement wire for that - does anyone have any ideas about that?

Re: Switching from CDI to stock stator setup

What makes you think it's some kind of special wire ?

Why not simply see about what gauge it is and find something close to replace it with ?

Or , just cut out the bad section and solder it back together with a bit of heat shrink to cover . (edited)

Re: Switching from CDI to stock stator setup

Bill Clinten /

damn okay that sounds doable - i know nothing about wiring clearly

Re: Switching from CDI to stock stator setup

Bill Clinten /

This is the nicked wire - it doesn't look like it actually ripped up the wire at all. Does it make sense that a messed up wire on the stator would still allow the bike to start and run but not idle? Or is it likely something unrelated to the wires on the stator? It ran fine before I started messing with the timing and stator plate

IMG_0421.JPG

Re: Switching from CDI to stock stator setup

There u go ,found something! Fix it right ,insulate it right , and see if that's your problem. Good work

Re: Switching from CDI to stock stator setup

Electrical tape. Or better yet, liquid electrical tape for something like that.

Re: Switching from CDI to stock stator setup

That wire looks partially broken. If so needs to be silver soldered and then reinsulated.

Re: Switching from CDI to stock stator setup

If that fuzz on the wire is suppose to be copper wire , it looks corroded . It may be so farther under the sheath . I'd cut at that point . Strip the sheath back to good clean wire and solder and heat shrink wrap .

As for effecting idle , maybe not unless the corrosion is severe . No matter , that needs to be taken care of before you can depend on it working as it should .

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