weak/erratic spark By kingcricket (Read 5,289 times)

[kingcricket]

thanks for all your input by the way even checking other bikes you have. The killswitch isn't a factor I did pull the black/white wire outta the cdi and nothing changed. I saw a similar thing on youtube where a guy had a 200s Honda 3wheeler that had weak spark like mine and he said he ground the coil straight to the chassis ground and fixed the spark but i already did that. That was probably two weeks ago by the way before the new parts were bought

[Bashan]

I just reread your whole thread and yes, the chances of it being the CDI with all of those swap outs is just about nothing. Let me think a bit, I'll be back.

Can you clarify the pickup a little? It gives zero v AC unless you move it closer?

[Bashan]

Jun 1, 2014 8:19:34 GMT -6 kingcricket said:

thought maybe a handle bar switch might be bad I don't know if any of the headlights wires could ground out on the handlebar and enable bad spark. I don't know how I could by pass the lights for the power or if I could just disconnect the yellow wire from the stator that powers the lights I don't know if that would need to complete a circuit or not.

That wouldn't affect the power to the CDI because the CDI is powered by the magneto coil, the big, fat, wrapped up coil that the red/black come off of. It is totally independent from the yellow and white. I'm not a big fan of unhooking the yellow to shunt power anyway. It loads up the white wire side of the R/R. It's a good way to burn up some rectifiers although I've run 'em like that. Your red/black AC feed to the CDI is rather anemic though. Possibly that's it. The 50 and change v AC might not be able to keep up with the capacitors. 50v AC is supposed to be the absolute minimum to produce spark. I bet that's it....what else could it be.....everything else is accounted for. But I'm going to look a little further. Rich

[Bashan]

So this bike is not running right now...at all...correct? Did you clean the carb and set the valves just to get that off of the table? If not we need to do that before moving on. The valves can get WAY off from sitting and it will not start if they're hanging open. Does the plug get wet if you crank it a while? I know you used starter fluid, I read that, but bad valve gap and a hinky carb can make everything off bubble. Rich

[kingcricket]

no it does not run they parked in drained the gas out of it and parked on a covered porch under tarp then they went to start it and nothing, the battery was dead so he jumped It and it wouldn't start so they thought the petcock was bad. It sat for 3 years before I got to it and I checked the petcock which was working fine. CleaNED the carberator, checked valve everything ok. Tried cranking it not even a putt sprayed starter fluid in the carb-nothing. I asked her uncle if it had spark which he said yes so I checked it and it was at nighttime and you could barely see the spark so its definetly not enough to run. But I cut slots in the holes for the pickup coil and slid it down and am now getting a steady .2 ac volts from it. Constant 58v from stator, and have tested the wires at coil unplugged black/YELLOW tested once got 30 down to nothing. Waited a little tried again got 12 down to nothing waited a while longer got 30 again down to nothing. I fully agree with you about a faulty CDI because I can't see any other wires on there that would interfere with that I was thinking about the yellow because I've heard of scooters not running with as much as a bad tail light, which I checked all light bulbs are good. and plug gets soaked after cranking it a while just won't light.

Note all my testing of volts are with ac volts on multimeter

[kingcricket]

they thought the petcock was bad cause the carb wasn't getting any gas but they didn't try to start it enough, so didn't even get the lines primed up enough to work right cause I get all kinds of gas.

[kingcricket]

I seen another thread on here while I was searching the web and saw a guy on this forum that was testing his with a new CDI that was putting 30v to nothing from CDI but never seen if he got it fixed or not thought maybe he had the same problem

[kingcricket]

Even though everything with valve gap and what not is correct right now my main goal is to get the right spark, I even drained all the gas out since I knew it'd be sitting for a while. even looking at videos on youtube with people with good spark I would kill to have there weak spark, so much better than mine. I Talk to guys at work about it and there all lost as well.

[kingcricket]

I tested it again but I unplugged the pick up coil wire and tested the output from the cdi0 which should be 0 and got 30, 20, 10 same. plugged it back in same. So would it be hard enough to believe that the pick up coil is bad and just bein plugged in is letting it complete the circuit with weak spark. cuz unplugged there's no spark but same reading from black/yellow

[Bashan]

OK, did you ever swap out the ignition coil, not the trigger. It is possible that it is faulty, even if it doesn't test bad, that it is draining the capacitors and not producing a decent spark.

You can check the ohms like this:

But that could look normal and still be bad. As cheap as they are I'd swap one. Please tell me you haven't already did this....

[kingcricket]

I have not checked it with ohms but i took a coil off a 230 suzuki and plugged it in and still had weak spark.

[kingcricket]

primary value .5 ohms secondary 7.8k ohms on ignition coil, and all my testing on the output from cdi are with them unplugged from the coil

[Alleyoop]

Have you checked the Ground wire from the motor to the frame if it is bad and not making good ground that would give you a bad spark. Is the spark erratic some times it sparks sometimes it doesn't?

If it is erratic i just fixed another guys bad spark on one of the other forums I belong to. He had the Trigger wire from the pickup coil plugged into the wrong wire going to the CDI. Told him to swap the two and VIOLA.
Alleyoop

[kingcricket]

it is just weak/erratic always there but the grounds are good and I haven't swapped and wires around as far as where they go on the cdi.

[Alleyoop]

So you never disconnected the wires coming from the stator and or pickup coil is that right? I am not talking about the wires right at the CDI I am talking about the wires from the stator and pickup coil that plug into connectors which IN TURN go to the CDI.
Alleyoop