DeTour

When you said the ig source coil had 2.1 ohms, is that kohms? I measured it and it's looking like 1.5 or lower. I put a test light in line with the black wire, to ground, and was not seeing anything when kicking over. So i'm thinking my problem is still down there somewhere. This things kickin my butt...

I got the points and condenser in there, still no spark. I ohmed the ignition coil between the plug wire and the base that bolts to the frame and get 11.6k ohms. Then between the plug wire and ig input and get the same reading. Then between the input and the frame base i get 2.2 ohms. So it looks like the primary is a little high, and the secondary is just about double the resistance that it should be. I guess i'll be ordering one of those too. ha ha... ugh. edit: anyone know a source for the ignition coil. Ebay had nothing, and bike bandit had nothing. I cross checked part numbers and i couldn't find anything else that matched.

Well i got a few things coming for me. Still waiting on the points and condensor and i found a set of foot pegs and a few nuts and bolts from ebay. One other question is that someone disco'd the oil injection a while ago. Do i need to modify anything to run premix? I've heard stories about main bearings with other bikes. Will it be a problem on this one?

One time i couldn't get my bike running i flipped it up side down with the gas tank, carb, and spark plug removed, and then kicked/pushed the bike over until there wasn't anything more coming out of the cylinder. And i think you should buy a compression gauge. It's a handy thing to have. If i can't get something to run i usually check for spark, change the gas, check compression, clean carb. generally in that order. Compression can be a very handy thing to know...

wow thanks, that cleared me right up. Left the plug over night then just let it run til it died. turned the gas back on and it ripped. so again, THANKS!

I know it's no yamaha. But my little 125 ts is running messed up. Last week it was running awesome. I parked it then 30 minutes later it wouldn't start or run with out the choke. Then it ran fine with the choke on. After that it wouldn't start at all. I just pulled the carb apart and it was clean as a whistle. I sprayed it out with some carb clean, put it back in, check to make sure i was getting a nice healthy spark and it fired right up with out the choke, which is fairly peculiar. When it started it sounded kinda puttery compared to it's usual purr. There was like an extra little pop in it. Wondering what anyone thinks this could be. Not to mention, i could only ride for 10 seconds then it would die out and not start back up. I'm confused. When i pulled the plug it was soaked. I was thinking timing. For grins i was also going to check compression. but i'm not sure where i stand now. Anyone?

Now that's dedication... Any chance with pics? But i've found alot of parts on ebay. And i don't know about shipping, but i've had alot of luck with bikebandit.com of course i'm in the US

I'm just waiting on points and condensor to come in. I probed around the coils and the main ig coil. They seem fine. I gotta say thanks for having patience with me. I tend to blow 2 strokes out of proportion i think. If i install the points and condensor and get some spark, i'll find an air filter, clean the carb out and ride it til my hearts content.

ya that thing is inline with the ig feed wire from the stator. So i can just disconect it?

That bottom diagram really clarifies things. It looks like everything is good. I can unplug the tach, speedo, and lights. The only thing that i haven't found in any diagram or book is that diode/condensor thing. I'm running without a battery so can i just eliminate that. Were these old bikes meant to run with a battery?

something just doesn't seem right with this wiring. I drew up a quick scheme of what my ignition wires are doing. Past this point, i'm not sure what the black wire does. But it almost seems like my kill switch is in the wrong spot. Continuity checks just don't seem right. But i keep getting real low resistance to ground at the kill switch wire with it disconnected. I'm just scratching my head here. Don't know if i'm looking for the wrong problem and i don't wanna dig too too far, even though just about all the electrical tape is off already ha ha. The clymers manual doesn't seem to have alot on this particular bike. Any chance someone would know of a better one, and where i could find it?

Just wondering if i'm chasing my tail here. But the p.o. decided it was a good idea to cut the kill switch wire in half and then twist the wires together. when i pulled the two apart while trying to find some spark and ohmed out the wire not attached to the switch to ground i find continuity. I have the connector going to the magneto unplugged. I had some really high resistance, then i unplugged the connector to the speedo and it dropped to .7ohms. At first, i un bolted the ignition coil and tested the wire that bolts onto the mount to ground and kept getting resistance to the frame. I unplugged every wire one at a time to try and detect a change and didn't find anything. Should I or should I not be finding resistance on that kill switch wire to ground? Finding resistance just didn't seem right, unless i'm missing something. How does the kill switch actually work?

I've had good luck with bikebandit.com however the points were fairly expensive. I lucked out and found points and condensor on ebay for 25 bucks shipped.

Your right, i don't know if you mean open a new topic or just introduce myself here. None the less not meaning to be rude. I'm rob, live in massachusettes. I haven't been riding that long. I just turned 24, well today and have only owned one bike before buying this yamaha, which was the 76' ts 125. I went to college for auto mechanics through the asset program, so know a little about a little. I dig the old vintage bikes, cars, watches, guitars, drums, anything. I don't like new stuff, because i'm cheap. I joined a bike forum mainly for information, if i gain a few friends along the way, fantastic. I want to learn about things that i own, or things that i want to own as well as possibly contribute whatever it is i have experience with. So now that that's over and done with, I got a manual coming in the mail as well as points and condensor. I know this is noob stuff, but that doesn't make it any less confusing ha ha. Either way, i ohmed out from the coil to the Kill switch and got 1 ohm. Then from the key switch to the harness that connects to the flywheel 4.? ohms. I'm not sure what it should be, but i didn't think that from the key switch should be dropping resistance. Might be my problem. I"m going to take it apart tomorrow and see whats up. Here's the picture of the magneto i was talking about with all the solder. And the bike itself. this is that funky diode looking thing i can't seem to figure out. Open one way, 500 ohms the other Well that's all for now.

Hey i just bought a DT 175 locally for 140 bucks. It's missing quite a bit. Here's the quick run down list that i made. Oil Injection cap Mounting bolts Injection lines Rear Fender bolts Kick stand Left foot rest Rack bolts Ignition switch screws Shifter seal Kickstart seal Handle bar bolt Handle bar grips Brake lever Chain guard "Exhaust Guard" air box screws and filter Front shock seals flywheel cover screws So not all that bad. Also been trying to narrow down why i don't have spark. I just ordered a manual, and i'm already leaning towards points and condenser. I unplugged the kill switch, tried a few different plugs, wiggled every wire imaginable, filed the points a little, sprayed it out with electrosol and aired it out. Still nothing. But i took out the thing that the points and magnetos bolt to and ohmed around a little bit. Someone made quite the mess of one of the magnetos by soldering wires to the coil. Alot of wires are just barely holding on, but i'm still getting fairly low resistance, like .9 or 1 ohm. A few questions, what should have what resistance, where. Also there's a diode looking thing with an arrow pointing away from the flywheel that has a black wire going to it. What should the resistance on that be. These old bikes always confuse me. But i want to know what i'm looking for when i sit there staring at it with meter leads in my hands. I"ll post up some pics if anyones interested.