I'm a Pickup Man and, Baby, My Truck is Broke - CDI issues afoot

DrGeorgeTompson (Alan) /

First thing's first. Queue this up to set the mood.

So I bought someone else's built Vesper motor (got damn you must be stupit!). Nah, I just like problem solving and I'm not a complete scrub. It is a good setup so I didn't really want to pass up on it, yolo. Also the ad said jet, bolt, and go. lol sure. We'll see about that sonny. It is this build actually, But I bought it from the guy that bought it from the guy that bought it from this guy or something. Idk it's a slut. I'm not gonna go too much into the parts rather focus on what needs to be discussed. I will try to lay out exactly what I have done so you can be like "you fucked up right here you dip shit". Maybe this will help other peoples.

Les go!

To start, I just slapped some jets and a needle in the 17.5 phbg. Stock idle and stock starter, stock needle, and I think 85 main? Idk, whatever the next step up from the stock size I had. Doesn't matter, that's fine. I also put a pull choke on it because I ride my shit all year and I like when it starts.

So it had sat for 2 years in the most recent owners stockpile. Why you'd buy something like thi$ and just sit on it is beyond me, but to each their own. So for safety's sake, I poured an arguably unreasonable amount of 2 stroke oil into so as to not have a dry start for the bearings and let it sit for a few days to properly cure, stirring occasionally. I was also waiting for parts in the mail. story of my life.

The CDI that is on it is a stock Piaggio ducati 3 coil job.

5 wires. Yellow and Brown are lights. Red is the pick up/pulsar coil, Green is the exciter/charging coil, white is a ground. Had one of the blue Ducati box/coil combos. Fancy!

All of the wires from the stator were initially black with zip ties or tape to identify the color, and that's fucked. I want the Italian flag colors dammit. So I bought fancy silicone wires that are extra noodley and soft and soldered them at the coils. fine and dandy. Cool!

Mounted the motor and the pipe and stuff.

I had mocked the wires up to the CDI box/coil and just kinda jammed them in there against the spades, just to make sure the timing was good and it would fire. Presto, worked fine. Fired up after a little starting fluid since I dumped so much oil in it. Smoke pours out the pipe like big king chief vape master, it was hoot. That eventually dies down.

This is where I think I fucked up, or at least this paragraph (mostly the bold part) will be what I attribute to my problems. It is now time to turn it off. I grab the black wire and touch the frame, Nothing. ok... how's this work then? Touch the white wire(ground), nothing. Touch the red wire, that cuts the spark, ok. Quickly remove it, engine keeps running. Touch green, also kills it, I let it shut off this time. Good to know. I start it up a few more times and kill it in a mix of red or green.

I cut my wires to length and add the female spade doodads on them and hook everything up. Now I have a hard time getting it to start. wat the shit. I go through the dance of checking for spark and timing and what have you and it eventually comes back. Cool, hook it all up proper again and it starts up.

The motor is now warm so it's time to try and rev the bitch to the moon and explode my clutch bell. I try to do so. RIN-DIN-DIN-DIN-DIN-DIN-DIN-DIN-DIN-DIN-DIN-DIN-DIN. Sounds like it's bouncing off a rev limiter like that old V-Tec. what the hell is going on. check the timing and it's firing like 180° off when that is happening and it is not revving very high. huh. that's probably not right. I kill it again and give it a think.

I try to start it up again. Now I have no spark at all. fuck. Did I kill the CDI box? probably. You stupid shit. whats more money into this amirite?

$75 for a box/coil with static timing is way too much money so the blue ducati can get bent. I'll find another way. So I look around and find and buy this Jog box since it has a curve.

Good deal!

and even though I have like 10 HT coils in my pile,

I buy a new one anyways.

$23 total shipped. Pretty damn good.

I hook all that shit up like so

It sparks, bike fires right up. Super easy. Lets see if it's still doing that weird shit with the off timing.

Yes. Yes it is. What the hell. I check the voltages from the coils and the exciter is pushing like 85VAC under a drill which is plenty considering the low speed. The pickup is doing like 5VAC which I think is fine. HM. I still suspect the pickup coil is bad. What about the pick up when it is actually running? So I took a video to share with the internut. I think Pickup Man should be done or done enough by now, so it's time for a new vid anyways.

This is from a cold start after sitting all night. The jetting is not great, but it gets the point across.

Notice how during the weird "rev limiter"esque effect the pickup coil voltage drops significantly. It also seems to get worse as the motor gets warmer and the rev limiting effect moves its way down the RPM range. This is good data I says.

So it's time to pull the coil and see if it's dickered. It has this big fucking hole in it. Im not sure if that is just a bubble from the epoxy pour or if I actually popped it. the pic is from after I poked it some with a screwdriver, just the tip and only for a minute mind you.

The symptoms remind me a lot of when people have problems with the cheap Treats e50/ZA50/505/whatever CDIs and the pickups fail on those all the time. I think I cooked it whist frying the cdi by touching the kill wire to the pickup wire. Like a goddamn idiot.

Maybe it was busted when I got it. Yeah that.

<.<

>.>

<.<

Definitely that

TL;DR is my pickup broke? Probably.

Re: I'm a Pickup Man and, Baby, My Truck is Broke - CDI issues afoot

Dirty30 Dillon /

These vespa cdi's are nice and reliable, but super sensitive to exciting the pickup. I'm fairly certain I have done the same thing on my CDI KS motor.

I'll be following along. Maybe even pull the Bravo out and start probing

Re: I'm a Pickup Man and, Baby, My Truck is Broke - CDI issues afoot

DrGeorgeTompson (Alan) /

> Dirty30 Dillon Wrote:

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

> These vespa cdi's are nice and reliable, but super sensitive to exciting the pickup.

I've been talking with Dos Cycles looking for a replacement part and that's what they said; It is pretty uncommon for them to fail. I have just ruled out the CDI box, unless the one I got is junk but odd are it's fine, and the signs point to the stator.

I dunno how much voltage that black kill wire on the ducati box pushes if any. Is it just an internal extension of the white ground wire? who knows.

Does anyone have a wiring diagram for the late model Vespas with CDIs? I am having a hard time finding something.(edited)

Re: I'm a Pickup Man and, Baby, My Truck is Broke - CDI issues afoot

Dirty30 Dillon /

I will admit that the hole in the pick-up is odd, and looks like a blow-through of the epoxy. I may have to pull the flywheel on my off-bike malossi motor to see if it has the seem defect.

Re: I'm a Pickup Man and, Baby, My Truck is Broke - CDI issues afoot

DrGeorgeTompson (Alan) /

> Dirty30 Dillon Wrote:

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

> I will admit that the hole in the pick-up is odd, and looks like a

> blow-through of the epoxy. I may have to pull the flywheel on my

> off-bike malossi motor to see if it has the seem defect.

Yeah I am almost certain that should not be there. Not sure if it poped or if its just been open and the inside got all messed up internally over time.

I really wish pulling the flywheel wasn't such an enormous pain in the dick on these engines.

"oh just disassemble the whole bike, ezpz" -Vespa Bro

edit: I now see you said off-bike. Yeah. do it, you won't.(edited)

Re: I'm a Pickup Man and, Baby, My Truck is Broke - CDI issues afoot

tl;dr

I hate to fault someone for being thorough and precise but it might be better to ask a simple question and comeback with these detailed answers to any response. With what you know it should be simple to guide you.

Is it a single wire pick-up or dual?

Re: I'm a Pickup Man and, Baby, My Truck is Broke - CDI issues afoot

DrGeorgeTompson (Alan) /

> frank dadog Wrote:

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

> tl;dr

>

> I hate to fault someone for being thorough and precise but it might be

> better to ask a simple question and comeback with these detailed answers

> to any response. With what you know it should be simple to guide you.

>

> Is it a single wire pick-up or dual?

I like information. I'd rather put it all out there and then have the questions come out to pick out whatever I may have missed. If you don't like to read, that's your prerogative ;) luv u bb

The post is more of a canvas to put my thoughts on and work through this with others/ provide a reference for anyone else that may find it useful. really i mostly get bored at work and want confirmation.

It is dual wire pick up and the ground looks of good health. The red wire is under my sausage thumb. Also a good connection.

Re: I'm a Pickup Man and, Baby, My Truck is Broke - CDI issues afoot

> frank dadog Wrote:

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

> tl;dr

>

> I hate to fault someone for being thorough and precise but it might be

> better to ask a simple question and comeback with these detailed answers

Fuck that. Well written and enjoyable all the way through.

Re: I'm a Pickup Man and, Baby, My Truck is Broke - CDI issues afoot

Dirty30 Dillon /

@george

Didn't get a chance to dissassemble my RV motor, but I should have time this weekend. I've been meaning to re-install the decomp anyway.

Re: I'm a Pickup Man and, Baby, My Truck is Broke - CDI issues afoot

DrGeorgeTompson (Alan) /

thanks jayson. I try to make things entertaining.

> Dirty30 Dillon Wrote:

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

> @george

>

> Didn't get a chance to dissassemble my RV motor, but I should have time

> this weekend. I've been meaning to re-install the decomp anyway.

take your time. I still don't know what i'm doing yet. Dos hasn't been able to find an OEM part for it and i haven't either.

I'm considering getting one of the Moby pickups Treats has.

I might pull the crappy one out of my Sachs and see if i can rig that up. It's just in the corner behind a lot of bikes...

Re: I'm a Pickup Man and, Baby, My Truck is Broke - CDI issues afoot

DrGeorgeTompson (Alan) /

K so i got bored at work today and went to the shop for a bit.

I tapped the middle hole and dropped the treats stator coil in like so just to see if it would work. Any clockwise rotation and the flywheel wont go on.

Ran it under a drill and the timing light and it does indeed spark. Albeit 30° or so advanced as one might expect from that orientation. I think i will try moving it to the rightmost hole and try to get it as perpendicular to the flywheel as possible. The voltage from the coil seems a little low and a proper orientation would help the timing a lot.

i feel like i will almost definitely need to run no woodruff with this however. We shall see.

I also cut open the stock pickup. Pretty sure that hole was just an epoxy flaw. It's doesn't look burned up or anything, but it is definitely broken now.

Re: I'm a Pickup Man and, Baby, My Truck is Broke - CDI issues afoot

DrGeorgeTompson (Alan) /

> DrGeorgeTompson (Alan) Wrote:

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

>

> I also cut open the stock pickup. Pretty sure that hole was just an

> epoxy flaw. It's doesn't look burned up or anything, but it is

> definitely broken now.

Also, Am i just being an idiot and this problem is jetting related? I don't think so.

Re: I'm a Pickup Man and, Baby, My Truck is Broke - CDI issues afoot

DrGeorgeTompson (Alan) /

I moved the pickup to the right most hole on a stack of washers so it’s raised a bit. It fits pretty good angled to be perpendicular to the flywheel. The spark timing is consistent now but still very advanced. Before it was jumping around a bit.

I only have a rough idea about how these things work so I can’t explain why this coil fires so much more advanced.

I will try lapping and the crank/flywheel and poping the woodruff key out and see if I can get it timed close later today.

I just want to start the bike and see if I have the same symptoms.

Re: I'm a Pickup Man and, Baby, My Truck is Broke - CDI issues afoot

Sounds like you need an oscilloscope in your life.

Re: I'm a Pickup Man and, Baby, My Truck is Broke - CDI issues afoot

DrGeorgeTompson (Alan) /

> Joe . Wrote:

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

> Sounds like you need an oscilloscope in your life.

Right? I said that while slamming my fist on a table at a coffee shop yesterday.

I have a new video I’ll post when I get to a computer.

Re: I'm a Pickup Man and, Baby, My Truck is Broke - CDI issues afoot

DrGeorgeTompson (Alan) /

So, WillD mentioned in another thread how these CDI pickups detect the change in the polarity, and that's what triggers the spark. So it happens twice per revolution. Maybe im just cutting spark under high engine speed cause it's not charging well enough?

Here's the treats pickup. A lot of vibration, it is too advanced still but it runs.

The same thing still happens, so i monitored the Charging coil this time. Does that seem like low voltage to you? I know more modern Vespa stuff will push 80+ under a drill. Idk what the output should be from the green wire.

Re: I'm a Pickup Man and, Baby, My Truck is Broke - CDI issues afoot

Flip the pick-up wires. If I'm not mistaken the top wire or leading wire goes to the white on the Ducati, with red going to the bottom or trailing end. The green acts as power and or kill if it's split.

After the late 90's Ducati used a rev limited but it's hit or miss with off brand boxes and curves/limiters. Hope this helps a bit.

eta: 80V AC seems about right. I don't think you have to worry about polarity with this CDI, but I'm confused if it's a CDI with the coil or a CDI without the coil you're currently running.(edited)

Re: I'm a Pickup Man and, Baby, My Truck is Broke - CDI issues afoot

DrGeorgeTompson (Alan) /

> frank dadog Wrote:

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

> Flip the pick-up wires. If I'm not mistaken the top wire or leading wire

> goes to the white on the Ducati, with red going to the bottom or

> trailing end. The green acts as power and or kill if it's split.

>

> After the late 90's Ducati used a rev limited but it's hit or miss with

> off brand boxes and curves/limiters. Hope this helps a bit.

>

> eta: 80V AC seems about right. I don't think you have to worry about

> polarity with this CDI, but I'm confused if it's a CDI with the coil or

> a CDI without the coil you're currently running.

This is why it helps to read the post.

It uses the pickup coil. It is not a 2 wire CDI like on a Kinetic. It is a Ducati 3 bolt stator that came on late model euro Vespas.

It is also not pushing 80+ volts anymore. idfk.

I'm just going to replace the whole stator with this one.

Re: I'm a Pickup Man and, Baby, My Truck is Broke - CDI issues afoot

*sigh

I read the post. It's confusing. Speaking as someone that's worked with the Ducati CDI's they can be the same and very different. I don't know anything about Kinetic.

You say there are 5 wires coming from the stator, and white is the ground. On the "fancy Ducati box/coil combos" the white wire isn't a ground, it's the 2nd trigger wire coming from the pulsar. Your picture of the trigger with the hole looks like a black wire, the new one has a white wire. Most of the time internal triggers are single wire. That's why I asked if the trigger is a single or dual wire, because it looks like a single but you're trying to use a 2 wire triggered CDI.

You can run a single wire trigger/pulsar to a dual wire but with poor results. And the results depend on the CDI, one type uses varying voltage to sense RPM and the other pulse width. AND, you'll love this, some have curve and some don't. It depends on who manufactured them and when. And there are 4 stroke versions that look identical.

That's if you were using the proper Ducati CDI. I believe the JOG box you have is also for a dual wire CDI so you probably have the same problem.

If you get the new stator do yourself a favor and get the Ducati CDI. You can find blue or black CDI/coils for $15 shipped without a rev limiter. It's tricky getting them from China because you have to know what you're looking for. I believe the pre-2003 Aprilia SR50 CDI isn't restricted so cross reference to that.

Re: I'm a Pickup Man and, Baby, My Truck is Broke - CDI issues afoot

DrGeorgeTompson (Alan) /

> frank dadog Wrote:

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

> *sigh

>

> I read the post. It's confusing. Speaking as someone that's worked with

> the Ducati CDI's they can be the same and very different. I don't know

> anything about Kinetic.

>

> You say there are 5 wires coming from the stator, and white is the

> ground. On the "fancy Ducati box/coil combos" the white wire isn't a

> ground, it's the 2nd trigger wire coming from the pulsar. Your picture

> of the trigger with the hole looks like a black wire, the new one has a

> white wire. Most of the time internal triggers are single wire. That's

> why I asked if the trigger is a single or dual wire, because it looks

> like a single but you're trying to use a 2 wire triggered CDI.

K.

In my original post, there is a picture of the exact stator i have. Here, i'll post it again.

Hey here's a Simo stator that's exactly the same but with a blue wire instead of a green one.

Weird how that white wire is on the stator plate shared with the charging coil, pickup coil, and light coils. It's almost like it's a ground or something. Potato Potato How bizzare!

(edited)

Re: I'm a Pickup Man and, Baby, My Truck is Broke - CDI issues afoot

There's a reason they use wiring diagrams instead of pictures in technical drawings. You can never capture every wire and every junction in a 2D picture. It doesn't mean shit if a green wire wraps around the back of a coil and goes into a junction and comes out pink with purple polka dots.

The pics are fine but all I'm saying is "color" means nothing. You have to trace wires from connection to terminus. The white wire you see coming off the stator plate might not be the same one coming out of the harness. It's not bizarre at all, it's quite common. The big manufacturers like Honda try to keep things color coded but Yamaha or even Ghinzao Chang might be slightly different.

I'm not trying to be a dick. I'm trying to pass on the knowledge I gained from considerable learning pains doing the same thing. If it comes off as condescending my apologies but I've tried to be very diplomatic. I could have just laughed at your wiring diagram and called you a dumbass and told you to go read the wiki but I've actually tried to help. :)

Re: I'm a Pickup Man and, Baby, My Truck is Broke - CDI issues afoot

DrGeorgeTompson (Alan) /

I gave a wiring diagram. I said I replaced the wires on the stator; there's a whole paragraph about it and why I did it. I think, JUST MAYBE, I know where they go. You can't tell me the color means nothing.

Here let me post it again just for you.

Read the original post. I appreciate the attempt at help but it's not really beneficial when you make suggestions that are not in the right direction and then give me shit for not giving you enough information. I get it, maybe I'm hard to follow as I ramble a bit, but the information is there.

Re: I'm a Pickup Man and, Baby, My Truck is Broke - CDI issues afoot

you said it yourself, but this is exactly what happens when the cheapo treats puch cdi fries the pickup but they also take out the CDI box with them lots of times when they do that. its kind of a chicken and the egg deal.

lots of cdi boxes will fry if you unhook the ground wire when they are running. i think your janky test wiring did that... been there myself.

your pickup was maybe fine from the get go?

there is a knockoff of that ducati box on alibaba for like 13 bucks, i got one hoping it would be a '1 wire' kinetic style but it isn't.

Re: I'm a Pickup Man and, Baby, My Truck is Broke - CDI issues afoot

DrGeorgeTompson (Alan) /

I could have had a few problems here because of my lack of surgical care with the CDI bits. That or I've been chasing the wrong thing and it's something dumb like a bad flywheel.

I definitely fried that Ducati CDI box with my neglect, er at least is just stopped sparking, which I could also attribute to the charging coil shitting the bed, maybe? I could check it at some point.

The jog box works good and I've been really careful to make sure everything is well grounded and such.

New stator comes today. I'll be sure to post my disappointment or otherwise. Fingers crossed.

Re: I'm a Pickup Man and, Baby, My Truck is Blastin' - CDI issues afigured out

DrGeorgeTompson (Alan) /

OH SHIT IT WORKS.

First i gotta plug the guys at Dos Cycles for hooking me up with a replacement part. They were super helpful and i recommend them for anyone looking for weird shit that's hard to find. Blake ended up pulling a stator off of one of his personal bikes and selling it to me at an awesome price with free shipping. It looks like it lived on the outside of a submarine, but that's not important. It even has the accessory coil that i didn't have previously. neat!

Did the same wire refresh and slapped it in. Starts right up and revs to the moon. Shit's gonna rip.

So, What went wrong and what have we learned?

I found this cool gif about how this crap works. It is relevant but imagine that it is triggering twice per revolution at 180° intervals since there is not a sensor that triggers once like on a tomos but it triggers when the poles switch which happens twice per revolution, my dudes.

Lets start with the pick up coil -

At this point, I don't think this was ever actually broken. I was just going off of what i have heard with the Treats CDIs failing in the past and this sounds pretty similar to the symptoms experienced when those crap out. So i figured why not replace it. It's pretty much the only replaceable part on the stator.

The pickup from the treats CDI has about half of the resistance of the Vespa pickup. From all my dope nasty clown chunking vaping experience i know that's either less wraps or larger wire used for the windings. i am thinking the latter but it is likely a combination of the two. Either way, it trips the CDI sooner.

So it still didn't work right. What's that leave us with? The CDI box and HT coil were already replaced so that's ruled out. There's only one piece of the ignition left.

The Charge/Exciter Coil

So when i was initially digging around on MA to try and find other cases of problems like this, i stumbled across this thread.

https://www.mopedarmy.com/forums/read.php?6,4134982

Similar sounding symptoms again but im like nah mine looks fine, can't be that.

Well i guess it was.

It is interesting to note that resistance of the Exciter that i took off was about 405Ω. The one I swapped on was 430Ω. so maybe it was shorted a few wraps internally or something maybe i melted it with the soldering iron and my ham fists? Either way, i am assuming the capacitor was not charging fast enough and did not have enough spark energy to jump the gap before TDC under the compression and fuel load.

I'll check the output voltage of the new exciter next time i'm in the shop for some data points for reference.

I am excited because this bike is gonna be a good time. Still gotta get the front wheel spaced and mounted proper before it'll be on the road again.(edited)

Re: I'm a Pickup Man and, Baby, My Truck is Blastin' - CDI issues afigured out

Hey man, I'm glad my post helped you. Your thread was very good to follow. You make reading it entertaining and thats kinda key.

So I'm back in this boat with a different bike and I changed the ignition coil to a motobecane ignaition coil (since they are "interchangable") and I still have the issue. Later today I will replace the pickup coil to see if that fixes the issue. If not, I will order a new regular coil for the puch CDI and go from there.

It's always a good feeling when you get these things up and running well. Wish me luck!

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