dt250Man

Ok, rings have been purchased and hopefully they come in tomorrow. Now that the magneto has been brought into the picture it does sort of make sense it could be it. None of my lights have been working except the the tail light; yet, the connections were gooding and giving resistance, I guess this could have been an early warning that maybe that magneto coil or stator were going out? I figured it was the wiring causing it when the bike ran... the spark plug has me baffled also; maybe it is getting wet and I am to blind to tell. well once the rings come in and i replace them I'll get to disecting the magneto if it doesn't work.

Ok, just inspected the reeds and they are in almost perfect condition; they open easily none were stuck and fuel flowed through them nicely. Also the starter fluid trick was to no avail ...now I'll replace the piston rings and see where that leads me. I did turn the motor a little with the reeds off to look at the piston and it seemed in pretty good condition; it didnt have any scratches or anything showing any major malfunction but i did notice that the oil i poured in earlier was now all over the piston. I guess it leaked through the seals, maybe thats what the fuel is doing and thats why the spark plug isn't getting wet?

I did try to start it with the compression boosted and still it didn't start. I'll go take a look at the reeds right now and see what condition they are in. Also, I'm gonna squirt a little bit of started fluid in the cylinder head and see once and for all if it is really getting fuel to the motor; however, I do suspect that it is. Another thing I did come across some parts for the bike pretty cheap at nwvintagecycleparts.com, has anyone heard of them? If so are they good quality parts?

I just redid the compression test wih full throttle and it only improved from 40psi to 50psi; than, I poured in a capfull of oild and it went up to 100psi. So I guess its its time for the good ol' rebuild, seeing as how I'm poor this will probably take ten years. I'll try to keep updating and see if anything new happens, also, does anyone know where I can get parts for this bike? I went to my local yamaha dealership and they said they don't carry parts ten years or older so any help on part numbers and where to find them would be great! thanks again for all the help

yes there is 2 stroke oil in the oil tank, its not full but I dont think its empty enough for it to interfere with the performance. Sorry to keep asking but do any of you know if 40psi is the correct compression for this bike? I'm begining to think that the piston rod blew or something...

I will check. If there wasnt 2 stroke oil with that not let it start up?

Yeah i hold it down and Kick it but nothing.

Just got the bike like maybe a month ago. Bought it and it would start right up and drive fine my brother and i would drive it around alot. I put the gas in at a Shell gas station ran about two tanks thru it. And one day i went to ride it around the block and it shut off on me. It shut of like it was running out of gas and wont start back up. And now even if i try push starting it from the top of my hill the Tires lock up and it just shuts off.

Ok i just tried push starting it and Nothing. It would turn over and Start for like a Brief secound and shut off right away. I tried giving it gas and it does nothing. Would a Video help anyone out with trying to find the problem?

Well i just got a chance to work on it. Put a new plug in and still nothing. The plug does not get wet so i took the carb out and stripped it and the jets are not clogged nothing really in there to make me think there is debris in there. I tested the plug and i still had a nice spark when i unplugged it and had it lay on the head.Does anyone know what the Compression is on these motors? I have no clue what it could be. Would having a Bad kill switch not let the bike start? I dont know where or what to check anymore. Any other reason why my spark plug wont get wet with fuel?

I'm in San Antonio if your close come on by and give me a hand. If your not a few pointers on what to look out for would be just as helpfull

I have pulled the fuel line off where it connects to the carb and turned the flow on and gas came out so its getting to the there. Also, I have have pulled the cap off the carb where the throttle line goes into it,because the throttle cable recently broke and I replaced and I noticed the the plunger and jet needle were both pretty wet with gas so I'm not to sure if that would be the problem. Could the fuel be getting blocked somewhere else? maybe in the bowl or something? I dont know. Another thing, how would I check the timing? do I have to pull the head off and check the chain and where is it supposed to be at? Third, I dont know what a TS is, sorry I'm still new to bikes can you elaborate on that. and finally would anything in my wiring cause something to short out and make the bike die like that because like I said in the first post the wiring is kind of rinky dinky. Sorry for so many questions guys, I'm just totaly lost on why it would do this. Any and all help is appreciated

the kickstart still cranks the motor but it just wont turn on, its like it just doesn't want to start. It does have a nice spark when I kick it; I checked the compression on the head and its at 40psi, is that good or bad? I looked and i can't find anywhere what it should be...

Hello I have a 78 dt250 and a couple days ago i was riding it around on the streets and it just shut off and now it wont turn back on. I have checked the spark and it is getting good spark there is fuel going to the carb and nothing jammed in the air filter. When it died it seemed like it was out of gas but before i rode i had top the tank off. I know the bike might have some bad wirring do yal might think that something shorted out? Any info would be great i miss riding the bike. Cliff notes. Took the bike out rode around and it shut off. Now it wont turn over, Checked the Fuel air and spark and made sure that it wasnt on engine off and it wont turn on.