Moby Malossi CDI Fried?

So I've got my Moby malossi/ducati CDI all set up. flywheel is seated well and timing is set to 1.8mm before top dead center. wires go from stator to box as indicated in the instructions and the box is grounded to the frame on a bolt that is clean and the frame (at the ground point) has been sanded and cleaned to ensure a good clean ground. From the box it is wired to the regulator which is also grounded well.

Continuity tests show the engine and case are grounded to the frame, but the thing just doesn't spark. The boot and plug wire are new and have been heat shrinked and are solid.

Spinning the flywheel by hand as you would with points yields no spark and ONE time when we I wrapped the flywheel with a belt and my buddy held the plug to the head while I pull started it he claimed it sparked, but on subsequent pull start tests I've gotten no spark.

What the fuck gives? Did I get a shit box? I thought these things were supposed to work well? I thought they were rock solid? Fucking CDI's.

Re: Moby Malossi CDI Fried?

Does your ignition low voltage coil put out any voltage? Does the trigger coil put put any voltage? Do the coils read continuity when disconnected from the rest of stator? (I.e., are the windings intact?)

Re: Moby Malossi CDI Fried?

Uphill Nater /

This I had not thought of and will check... Hmmmm...

It seems like the least likely thing to be fucked, I mean I've only ever once encountered a bad copper winding coil.

So it is possibly that my coils could be fucked?

I knew I should never go CDI. How the fuck are you supposed to trouble shoot a magic computer box thing. Argh. At least with points I know what the hell is going on.

Re: Moby Malossi CDI Fried?

so is this your first installation of it? malossi is usually pretty decent quality so id be suprised if it came to you messed up. if you havent put miles on it to potentially damage it i would be more inclined to say install error. sorry, i hate when people tell me that too, and you seem pretty confident in your work.

ive had trouble with my moby cdi too (the treats version, of much lower quality) and the best advice i can give you is to get the resistance readings of all your coils (mainly your primary) on a _functioning_ stator plate. someone else on the forums may be able to grab them for you. then, in times like this, you can compare your coils to the functioning ones and get a good idea if theyre fried or not. pretty much the only thing i can think of to try to investigate black magic box situations like this.

on my cdi the functioning coils were 350 ohms and when i blew them they went down to 150. so the difference was night and day for me, maybe it will be for you too.

Re: Moby Malossi CDI Fried?

I've put alot miles on my malossi cdi, you should post photo of the wiring into the cdi box. Also using a drill or something to spin the flywheel, check voltage output of the cdi ignition coil on the stator. I can check the resistance of the pulsar/pickup sensor on my malossi/ducati. The stator/cdi box is the exact same as vespa.. LX something or another

Re: Moby Malossi CDI Fried?

The first two brand new boxes I got for that same cdi were junk. One sparked intermittently the other was totally dead. Testing on another bike confirmed it was the boxes. Totally possible you got a junk box

Re: Moby Malossi CDI Fried?

Uphill Nater /

Thanks Naz, I'll get on that ASAP- I'm off to work here in just a bit, but perhaps early tomorrow or tonight when I get home.

I feel pretty confident in my installation, which is weird as I can quote a friend recently saying about me "He's got an unnatural hatred of wiring and electrics..." A friend who runs a Peugeot version of the same CDI help me go over the installation-

Oh and on your advice, Mr Naz, I'm grabbing up a Lambretta Ducati CDI box for 10 bucks of off Ebay. Can't hurt.

Re: Moby Malossi CDI Fried?

Double check all your grounds, I had the same problem getting mine set up. It turned out to be a missing ground inside the headlight bucket. Another issue I had was getting the conductor of the sparkplug wire to get a real good bite on the the screw inside the coil.

Re: Moby Malossi CDI Fried?

Uphill Nater /

I still haven't gotten out to the garage yet, but just checked this.

So, crackstar, yours wouldn't work when your lights weren't properly grounded? That seems odd to me. I don't have my lights hooked up at all.

Re: Moby Malossi CDI Fried?

Probably not his lights, but the tangle of wires inside a peugeot headlight.

Re: Moby Malossi CDI Fried?

You have the light circuit grounded out? Do you have one exposed tab on the VR not connected to any thing? If so, connect that to ground.

Every thing in a CDI system "has" to go to ground, ALWAYS. cranking an engine over for, lets say a compression check, with out the spark lead being grounded out could lead to frying the magic in the black boxt

Re: Moby Malossi CDI Fried?

you don't have something plugged into the kill tab on the cdi box?... well other then the kill switch. I know it's a kinda silly question, but start with basics. :-)

Re: Moby Malossi CDI Fried?

Uphill Nater /

Alright alright... I'm tired but my brain is always wrapped around this. So here's a picture. The stop tab on the box goes off to a toggle switch in the stash box that grounds to a fender bolt. When the tab is ON the circuit should ground and thus kill the bike. When we initially tested the bike and got it to spark that switch was not installed. One tab on the regulator box is ungrounded but the box itself is grounded. Is that where I fucked up? I guess I'll be testing that tomorrow.

Re: Moby Malossi CDI Fried?

Looks like a very truncated version of my mistake. Hook up the lights you won't be sorry for long. Its a nice lots of watts. But you have power from the lighting coil going from the stator to the VR, but its not going to ground after the VR.

Re: Moby Malossi CDI Fried?

Uphill Nater /

Shit, alright. I hope I didn't fry this thing.

Re: Moby Malossi CDI Fried?

I don't think you did.

Just keep in mind that CDI spark looks different than points spark.

Feels very different too, if your arm goes numb you know you have it right

Re: Moby Malossi CDI Fried?

Uphill Nater /

Well, headlight hooked up and grounded and still no spark. Then I tried just grounding out the headlight tab, still no spark. So I tried pulling the plug wire and boot and I reattached them- guess what, amazingly still no spark.

Re: Moby Malossi CDI Fried?

I tried, sorry...

I still think its not fried and you will find something embarassingly "school for the gifted" simple that will then get you spark

It just seems so similar to my situation, one spark, then no spark, then no spark, then wondering if I fried it, then redoing everything twice till I found my error.

Re: Moby Malossi CDI Fried?

Uphill Nater /

I keep looking for it. I really want it to be a simple basics fuck up. Ran continuity tests on almost every wire I can access. The plug wire was shitty so I replaced it. Still no spark, replaced the cap, still no spark. Pulled flywheel and check continuity from all wires to magic black box, all fine. Checked all grounds including lighting grounds and kill switch grounds, all good. Brain in pain. Getting new box from UK for cheap. Will try new box. If that doesn't work lighting bike on fire.

Re: Moby Malossi CDI Fried?

dude just like you told me with my hobbit, don't give up.

Re: Moby Malossi CDI Fried?

Didn't you tell me to stick with points and not to use magic boxes because how the fuck do you troubleshoot them? Well, good luck. I hope the new magic box works for you. I'd really like to see that bike run.

Re: Moby Malossi CDI Fried?

with cdi, you usually need to spin the flywheel a bit faster to get spark out of it. I use a hand-held CORDED drill to spin my flywheel while testing spark and checking timing, it'll spin the motor at close to 2k!, Continuity doesn't always show everything wrong within a circuit, a single strand of a multi-strand copper wire can have 1 ohm of resistance and show up good as continuity, but it can't carry the amperage needed for any electrical consumer. Check what your voltages are coming out of your stator going to the cdi box with the motor spinning (drill) Check to see if you're getting voltage to the coil from the cdi box. You can see if your pick-up coil is generating voltage as well. Cdi's are pretty basic, maybe not as much as points but still pretty simple.

Good luck.

Re: Moby Malossi CDI Fried?

Nate, what did you do with the origianl braided ground strap? run that from your common ground on the VR to the engine pivot bolt, all inbetween the spacers and shit

Re: Moby Malossi CDI Fried?

Try attaching another ground from the engine to the frame.

Re: Moby Malossi CDI Fried?

nevermind....very first post....engine is grounded to frame.

Re: Moby Malossi CDI Fried?

Uphill Nater /

Bumping it up.

So today I installed a new box- and the problem doesn't seem to be the box- because I still don't have spark.

So we ran voltage tests on everything- pushing the bike around while my buddy Matt held his tester. The results- The Green wire into the box provides constant voltage as does the yellow lighting wire. They provided no voltage at all- no pulses, nothing.

I also pulled the stator and the coils and reinstalled them, and we checked the continuity on the coils and they are intact.

Oh and I put in another redundant ground.

What do you think? Bad pickups? I honestly have no idea. I think I got a bad unit- 2 bones down the drain?

Re: Moby Malossi CDI Fried?

Uphill Nater /

Sorry, I meant to say the red and white wires provided no voltage or pulses at all.

Re: Moby Malossi CDI Fried?

Nate, you know I don't know shit about cdis but ya know how the frame of the Hobbit isn't grounded? Maybe check your Moby ground by hooking the ground clamp from your welding machine to your subframe while the welder is turned on. Just an idea.

Re: Moby Malossi CDI Fried?

Uphill Nater /

The engine is grounded to the frame, by the exhaust, the spring and redundantly- by a wire from the engine mount bolt to the underside of the tank.

Re: Moby Malossi CDI Fried?

switch your multimeter to hz setting and then test the wires coming from the pickup again. It should read whatever rpms you are turning the motor at. If it does not then the pickup is bad.

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