DT125R 2002 Won't start for love of god
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Bought DT125R 2002 couple of days ago bike wouldn't idle and required choke to start, came home started playing with idle on carb its Mikuni 28SS as soon as i touched idle screw it wont start i kicked it probably couple hundred of times trying to get it right, cleaned carb cannot see anything wrong, sparks is short but blue guess thats fine, filter is clean and oiled, fuel geta into carb, looked at side stand switch its also okay. While playing with
screw i would get it to run on like 200rpms per minute for 3 secs could it be coil? Cdi? Im going crazy here. Keep in mind it ran fine before i bought it only sus thing was it hitting rev limiter as its limited to 7k? And 80kmh.. -
Here is link to couple fo videos how it runs/doesn't..
https://gofile.io/d/NdQhLVbX -
Forgot to mention reed valves are also good no cracks sit nice and tight, bought repair kit for carb waiting for that to come and also bought some cheap carb link down below, as far as i can tell everything in carb is original, has athene aftermarket exhaust.. https://www.motor-x.com/p/carburetor-moretti-parts-yamaha-dt-125
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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.
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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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@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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@hannahharris ordered bunch of original parts for original carb as i didnt know i was missing rubber gasket at airscrew, plus original coil assy and some other bits and drops including battery while im waiting for that i will do some cleaning and sorting out
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I would say that both @hannahharris & @joshuaseward look like bots to me.
It's difficult to say whether what they are saying is completely accurate or not, sounds feasible
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I would say that both @hannahharris & @joshuaseward look like bots to me.
It's difficult to say whether what they are saying is completely accurate or not, sounds feasible
@Calum well i have an update, im not expert electrician by no means but i know some stuff, started taking everything off and tested bunch of stuff, first of all coil is gone, it test OL on every combination of terminals possible, so good i ordered genuine one, i just dont get why it still sparks. Power valve on servo has been messed with the cables are way too long and look like they have been wraped around te servo rotor or whatever but i cannot get bottom part out near engine as one screw is stripped and i didnt have time to deal with that, so i will be ordering new cables probably when i open bottom part as its possible its been pinned. I have one question and im not sure if thats normal or what, i have 7ohm resistance on battery terminals, when key is ON and if on beeper it beeps, when key is off it doesnt beep and resistance is OL..
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Another update, seems like it was fitted with powervalve servo from tzr125, hence why cables are crossed but still follow 1-1 2-2 arrangment i need to wait for battery to come in order to see if thats what setup should be in order to open properly
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I may have stumbled across something and i need your help, new geniune coil, snorkel, reed valves, everything nice and seal same issue runs bit longer but nothing bogs down as soon as i touch gas that being said should there be a brass ball in the middle hole of the carburator? From the intake side picture uploaded in file? If so what is its purpose, can i plug it in?
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I may have stumbled across something and i need your help, new geniune coil, snorkel, reed valves, everything nice and seal same issue runs bit longer but nothing bogs down as soon as i touch gas that being said should there be a brass ball in the middle hole of the carburator? From the intake side picture uploaded in file? If so what is its purpose, can i plug it in?
@calum would you know? If it needs to be plugged there could be my huge air issue..
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