Good God what happened? Tomos...hot wires=no spark

So I'm cruising along at top speed and the engine starts running funny. I pull over and cut it and it won't start up again(mean while my now really hot engine is burning the wires that are touching it). So I'm trying and trying and I notice that the wire houseing has melted on the motor fins.

Only the outer most third layer off insulation melted...but it started to melt the layer that encases the black and yellow wire coming out of my A35 engine. Far as I can tell it didn't come close to melting the wires; probably over heated them though. So I pull the plug and realize I have no spark.

Questions: What have I done? And what can I do to fix it? Pretty obvious right?

1107205272_gort.jpg

Re: Good God what happened? Tomos...hot wires=no s

Jason Luther /

looks like your wires melted into a robot. first get as new plug. those wires could have been melted for months. if that doesnt work, splice some new wires in and see if it works. then splice them permanently.-jason

Re: Good God what happened? Tomos...hot wires=no s

Opps...wrong photo attachment, you know nothing. You hear me? Nothing!

Yeah...when this all went down I put a plug I had under my seat as a spare in and still no spark.

Where do those wires go inside the engine? Do I have to open the whole motor up if I want to get to them, or just remove the cover and the fly wheel?

Re: Good God what happened? Tomos...hot wires=no s

Jeff Strahle /

no just take off the left hand engine cover that is over the magneto. the two wires go into the stator plate and everything with the magneto and such thats under there.

Re: Good God what happened? Tomos...hot wires=no s

Does anyone know how heating those wires could have caused this problem? Did it effect the magneto or ignition coil?

I'll replace the wires and see what that does. Thanks for the info. I'll be sure to spare you guys of the doom I plan to unleash with my robot army.

Re: Good God what happened? Tomos...hot wires=no s

Jason Luther /

i wouldnt even go that far. just cut the wire behind the burn (toward the engine) and solder, or get a crimp on splice, a new wire to the coil, or wherever it goes. im assuming there is at least a few inches of wire coming out of the motor before the burn. at least do a continuity test of the wires before you cut them though. like i said the wires could have been melted for months and there could be another reason for the non-spark. -jason

Re: Good God what happened? Tomos...hot wires=no s

Don Pflueger /

test the wires with an ohm meter to determine which ones are good and which are bad. when you find a bad one, then splice a wire into only that wire. get some shrink tubing from radio shack and slip it over the wires where they are melted to seal them up and prevent them from shorting out against the frame or each other, and it will keep them from corroding. i doubt you caused any damage to anything else. you just need to sort out the trouble spot which will be on a blue or black wire since those are the two that control ignition on a tomos.

Re: Good God what happened? Tomos...hot wires=no s

I would want to know what melted the wires in the first place. That engine must have gotten real hot to melt them and that doesn't seem right. The cylinder head and jug are the hottest parts of the engine and there are no wires near them. For the engine to get that hot near the magneto and clutch, something has to be out of wack.

Re: Good God what happened? Tomos...hot wires=no s

No, the wires were resting right on the jug. Plus it's an Airsal kit and that aluminum gets pretty hot.

Re: Good God what happened? Tomos...hot wires=no s

Don Pflueger /

actually, the area around the exhaust port is the hottest. maybe they didnt get hot bur rubbed against something? or dropped down onto the exhaust header?

Re: Good God what happened? Tomos...hot wires=no s

Thanks to both of you for the clarification. I feel better now. I went and looked at my moped and for the life of me could not figure out how those wires could have melted. :>)

Re: Good God what happened? Tomos...hot wires=no s

Don Pflueger /

i cant understand it either. really, the only thing that could cause them to melt would be;

1) to lay against the exhaust header

2) a direct short to ground which would have heated up the wire strands and melted the sheaving all the way down, not just in a small area

3) an exhaust leak blowing directly on the wires, which would have to be located real close to the leak.

or maybe they were melted at an earlier time before he rode the bike. maybe a drop light or something layed against them. i doubt a cylinder would get hot enough. if it did, its running seriously lean.

Re: Good God what happened? Tomos...hot wires=no s

Let me clear things up. I had way too much wire coming out of the motor. I cut off 5 inches of wire and still had plenty left over. now it's well away from the fins and I have lights and everything...but still no spark. So I'll change out the coil and regulator from some spares and see what's up.

You can see in the attached photo, between the two sections of cut wire I'm showing, the melted plastic on the fin.

Lesson:

keep a tight ship on your shight' and everything will run right.

Keep your goose on a noose and the shit will vibrate loose.

That's what crazy old grand pappy used to say.

1107279387_p1010950.jpg

Re: Good God what happened? Tomos...hot wires=no s

Don Pflueger /

your voltage regulator should have nothing to do with spark. and coils raely ever go bad. i would make sure you have power coming from the blue wire, and that the black wire is grounded. the yellow is power for your lights. i dont see how you could have 5 inches too much in a stock wire harness. you may have pulled it too tight up top now and when you steer it may pull it apart.

Re: Good God what happened? Tomos...hot wires=no s

Okay, I have alittle voltage meter with nothing but a light that glows. When I hook it up to the red prob to the black wire (coming out of the motor) and ground the black prob I can crank the peddle really fast and make the light glow. The yellow wire will not make the light glow. However I have all my lights including head,rear and brake.

I did try a different voltage regulator and coil that I know work...still no spark. I'm stumped.

Re: Good God what happened? Tomos...hot wires=no s

Bump, help.

Re: Good God what happened? Tomos...hot wires=no s

Don Pflueger /

here is the a35 service manual

http://www.mopedriders.org/article_view.php?faq=2&fldAuto=21

read thru it. there should be a section that tells you how to test the electrical parts. on every tomos ive worked on, yellow produced 6 or 12 volts depending on the magneto, blue produced 3 to 6 volts depending on the magneto, and black was ground. but i havent worked on any newer models than 2000. i doubt they have changed much, but maybe the color codes have.

here is the wire diagram which shows yellow as being a power lead which goes directly to the regulator. it does show black as a power lead going to the ht (ignition coil). blue should be ground, if it has a blue wire

Re: Good God what happened? Tomos...hot wires=no s

Don Pflueger /

sorry the pic came out so big.

Re: Good God what happened? Tomos...hot wires=no s

At least I can read the colors.

Re: Good God what happened? Tomos...hot wires=no s

Don Pflueger /

yep. they are usually printed in slovenian.

Re: Good God what happened? Tomos...hot wires=no s

So I still got nothing everything the yellow wire is hooked to works, though I can't make the glow plug on the tester come on. It comes on on the black plug though...but I have no spark. I'm not sure if I'm even using this tester right...but I still can't imagine what's up. I'll try to get my hand on a ohs tommorrow.

Re: Good God what happened? Tomos...hot wires=no s

Don Pflueger /

your tester may require too high of a voltage or wattage to light up on the black wire. try to disconnect the second black wire that runs up into the harness towards the handle bars and then test for spark.

Re: Good God what happened? Tomos...hot wires=no s

That's just it...it lights up the black wire. But the yellow one deos not light it up, however I have everything but spark.

I've taken the side cover off and I'm about to pull the fly wheel. While I'm in there, I was wondering if there is anything I should be on the look out for?

Re: Good God what happened? Tomos...hot wires=no s

Don Pflueger /

you probably wont see anything. unless one of the coils is burnt up. you need to do an ohms test on each of the coils to see if one is bad or not. but really, you need to use a meter to measur the output of the wires rather than a test light.

Re: Good God what happened? Tomos...hot wires=no s

I'll go pick up a meter right now. Could you give me the low-down on testing each coil Donp?

Re: Good God what happened? Tomos...hot wires=no s

Don Pflueger /

you just need to separate each coil and test for resistance. i dont know what the values are, but a bad coil will show a large resistance. thats why i posted the link to the repair manual. but first test each lead with a meter to see what its putting out exactly. they are measured using an ac scale.

Re: Good God what happened? Tomos...hot wires=no s

The manual is very confusing. I don't have any special tools...much less a flywheel puller. I'll get it off though, I've got a working method.

Once I aquire a ohms how do I test the lead? What is the Lead?

Re: Good God what happened? Tomos...hot wires=no s

Don Pflueger /

the lead is the wire coming out of the magneto or off the coil.

Re: Good God what happened? Tomos...hot wires=no s

Do I need to pull the fly wheel to get to the lead? Does the magneto need to be rotating to test?

Re: Good God what happened? Tomos...hot wires=no s

I hooked up the OHM meter to the yellow wire and it gives me 12 volts. When I hook up the black wire the same way I get a big fat zero.

So I pulled the fly wheel and I found the coil plates that interact with the wheel to be a bit rusty. I steel wooled them clean. Then I managed to break the little black plastic housing that goes over the magneto end of the wires where they connect to the copper (yellow wire) and silver (black wire) wire coming from the coils. Nothing alittle electrical tape won't fix for now.

All seemed well so I put it all back together...still no juice in the black wire.

Realize to DP that I'm the same guy who posted last week about hearing some crackling coming from the motor at top speed. Some folks thought it was too small a jet (64) on my Airsal with estroil exhaust. I felt the chop was looking good and left it.

Any more input? Could the black wire alone be shorted? It looks brand new. How about the coil its connected to? I don't know. I'll have to pull the magneto from my buddy's parts bike on and see what's up. Thanks for all your help.

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account