DT125R 2002 Won't start for love of god
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It's in my experience that my DTR never started without choke, so that's normal. It needs to get to temperature and then you can remove the choke.
Sounds like you need to strip and clean your carburetor, based off what you've just said.
It could be float level height if it's just shutting the fuel off before it's even getting a chance to get into the bowl.
Strip the carb, removing the atomiser and properly clean the carburetor in and out, being careful not to damage it as the components are brass and delicate.
The engines are very basic and provided you've got compression, spark and fuel ,it'll run.
If you can confirm that it's got spark and fuel, then check the compression for the engine, should get around 140PSI. Anything below 90 PSI and your engine is going to need an overhaul.
@Calum i bought psi gauge today but i wont be near bike till saturday, so i guess thats when i will update on numbers regarding compression, bought also new coil just incase, and have spare cdi on hand so we will see thanks for info!
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Only use genuine coils. The cheap orange ones simply don't work so make sure it's a genuine one.
@Calum bought replacment coil as there wasnt any original, currently orange one is in, rebuild carb changed everything other then air mixture screw as it didnt come in kit. Starts runs poorly on idle same as before but little better and when touching throtle it dies i tried turning the screw milimiter by milimiter no luck, needle was at 3rd point from bottom i moved it to 2nd one same thing, throtle valve is a little worn on the idle screw where it touches the screw like a small dent but i dont think that should be causing this much of an issues, compression is at 130psi so that should be all right if anyone has any idea feel free to suggest im going crazy here
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I never could get my DTR to run on those shite orange coils.
There is a genuine coil brand new stock there.
I found that the bike would idle but refuse to rev and cut out. Rode it back from Wales like this back to Cheltenham, couldn't rev past 4k, was a nightmare.
So lesson learned on that one sadly. My brother had EXACTLY the same problem with these type of coils on his RD350. So it could be something as simple as that.
Make sure you've got good earths to the frame as well. Has the frame been powdercoated recently or anylike that?
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I never could get my DTR to run on those shite orange coils.
There is a genuine coil brand new stock there.
I found that the bike would idle but refuse to rev and cut out. Rode it back from Wales like this back to Cheltenham, couldn't rev past 4k, was a nightmare.
So lesson learned on that one sadly. My brother had EXACTLY the same problem with these type of coils on his RD350. So it could be something as simple as that.
Make sure you've got good earths to the frame as well. Has the frame been powdercoated recently or anylike that?
@Calum where should i look for earth? Bikes was bought from 15yr that used zipties for everything from coil to servo of valve... so i woudnt be suprised if it was earth even.. here the link where am at now https://gofile.io/d/HHUZA4pa i don't think its carb issue cause at every setting on needle and on air screw result is pretty much the same, if it was carb i would expect it to run poorly or rev high or something but thats not the case here..
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@Calum where should i look for earth? Bikes was bought from 15yr that used zipties for everything from coil to servo of valve... so i woudnt be suprised if it was earth even.. here the link where am at now https://gofile.io/d/HHUZA4pa i don't think its carb issue cause at every setting on needle and on air screw result is pretty much the same, if it was carb i would expect it to run poorly or rev high or something but thats not the case here..
Also i dont know if it matters i dont have battery inside of it
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You don't need a battery but you'll want a battery.
Yeah, looks a bit of a basket case that bike and you're asking us to make wild guesses when it could be anything.
You've not running a snorkel, that engine does not sound crisp at all, you can tell it's swamped with air and it's struggling.
Without a battery you're relying on the generator making sufficient power to do all the lights and make 20'000 volts at the spark plug lead, coupled with the poor wiring, bad earths and the second rate coil, it's no wonder it's not running right.
You need to get yourself a battery.
Sort the wiring out
Get a genuine coil on there
Get a genuine snorkel fittedMake sure you got good grounding from the chasis to the negative terminals.
Search on this forum for the wiring diagrams as there are many different grounding points, different for different years, so ensuring you got the wiring for your model will ensure you capture the grounding points.
Ultimately there is not a lot to these engines, but you have to have the basics done right, otherwise we're stating into the abyss trying to help you.
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The missing battery is likely a bigger deal than you think on this bike. Without it, the regulator has nothing to buffer, so voltage can spike and drop as revs change, and the CDI won't get a stable supply. That alone can cause a weak, erratic spark even if the coil and stator test fine. Get a known-good battery in there first, then clean and check the main earth points at the frame and engine, not just the coil bracket. The ziptie wiring from the previous owner needs tracing properly. Fix the basics before chasing the carb again.
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The missing battery is likely a bigger deal than you think on this bike. Without it, the regulator has nothing to buffer, so voltage can spike and drop as revs change, and the CDI won't get a stable supply. That alone can cause a weak, erratic spark even if the coil and stator test fine. Get a known-good battery in there first, then clean and check the main earth points at the frame and engine, not just the coil bracket. The ziptie wiring from the previous owner needs tracing properly. Fix the basics before chasing the carb again.
@joshuaseward yeah thats what i will be doing next couple of days, it looks really worse then it actually is. Just needs some proper cleaning and sorting out,engine is bone dry it was rebuilt like year ago and wasnt driven much. When coil arrives if it doesn't start with harness sorted and carb rebuilt i will probably swap out carb for tmx30 or something like that. But i think problem is going to be coil as it was bugging a little (like hitting rev limiter at random) while it was still working and when i put gas directly in cylinder it doesnt start.
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The detail about it cutting out like a rev limiter before it died points hard at the coil rather than fueling. If it were the carb, dribbling gas in the cylinder usually gets at least a cough. While you wait on the coil, cleaning those earths and getting a battery in the circuit costs nothing and rules out the regulator spiking the CDI. A TMX30 is a big jump from stock, so I'd get it firing on the original carb first before swapping. Bone dry from sitting is one thing, but make sure the crank seals aren't dried out too.
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