DT125R ARCHIVE

Motorcycle_Enthusiast · DTR Member

DT 125 R Bogs down in high rev range

CooS · DTR Senior Member

My advice would be to take the snorkel of top of the air box under the seat to see if that works as it will allow more air in! And if that doesn't work up-jet and checking your plug to see it's health! Ow and you are using the choke properly aren't you?up = choke on (when cold) down = choke off (when warm)

Motorcycle_Enthusiast · DTR Member

Yup the choke is off when warm.. (DOWN) As for the snorkel thing I want to leave it on as it's an off road bike so will stop stuff getting sucked in, I've also cleaned the air filter so I know thats not clogged. The bike does want to go, but just struggles at high revs.

CooS · DTR Senior Member

In that case mate I would check your plug to see if you need to uphet your carb! Best to get all the obvious possible problems out the way first.

Motorcycle_Enthusiast · DTR Member

Why would I need to upjet my carb if it's runing on standard jetting, airbox and pipe?
It's not the plug cap either, checked that too. 5k Ohms

-- Edited by Motorcycle_Enthusiast on Monday 17th of October 2011 07:25:14 PM

Seiki · Admin

Process of elimination

Have you read through the tons of threads covering the same issues? If you try one thing and it doesn't work then it has to be something else ...

I'm sure if you read a little you'll find someone else with the same issue. Hopefully they bothered to update their thread with a solution

Motorcycle_Enthusiast · DTR Member

Well it's not the carb, swapped it.
Isn't the cdi.. Swapped that too, just incase.

As for reading through threads I have read a few but the end result isn't allways posted, hence my post!

I will search some more and see! Cheers

-- Edited by Motorcycle_Enthusiast on Monday 17th of October 2011 07:37:48 PM

Dingle001 · DTR Senior Member

Sounds like a mixture problem to me and as youve swapped the carb it sounds like its running weak. Previously, I have read threads on here of misfires at high revs which have been power valve problems but if you're having problems at low revs then this cant be the case.

So if its running weak I would suggest you check the carb inlet rubber for leaks and the joint with the reed block. Otherwise it sounds like crank case seals or possibly very worn rings/bore. Does it start easily hot and cold? If it does then I am completely wrong on all counts

Motorcycle_Enthusiast · DTR Member

Dingle001 wrote:
Sounds like a mixture problem to me and as youve swapped the carb it sounds like its running weak. Previously, I have read threads on here of misfires at high revs which have been power valve problems but if you're having problems at low revs then this cant be the case.
So if its running weak I would suggest you check the carb inlet rubber for leaks and the joint with the reed block. Otherwise it sounds like crank case seals or possibly very worn rings/bore. Does it start easily hot and cold? If it does then I am completely wrong on all counts

It runs OK Low-Mid revs.... It's in the high rev range it bogs out! The mixture screw is 1+1/2 turns out, + clip is in middle of needle. It hasn't got any air leaks as I sprayed carb cleaner on all the rubbers and the revs dont pick up. The powervalve is dissconcted and I've pinned it fully open. Starts after about 3 kicks when cold, easier once warmed up.

tripr · Guru

its all a prosses of goin through everything tried adjusting the needle height ... ht coil an leads all good ....could always try pulling the airbox snorkle for a tester it only takes a min
mine was a pain for a while at high revs not long back an i thought it was allsorts turned out to be the ht connection

good luck with it m8

does it happen to you when pull the throttle back slowly or just when you rag the throttle open over 3quarters

-- Edited by tripr on Monday 17th of October 2011 08:11:34 PM

Motorcycle_Enthusiast · DTR Member

tripr wrote:
does it happen to you when pull the throttle back slowly or just when you rag the throttle open over 3quarters

-- Edited by tripr on Monday 17th of October 2011 08:11:34 PM

It happens in the top rev range if you open it up slowly or whack the throttle full open.

Just doesnt come onto the power like it should, splutters like a dog!

tripr · Guru

I cant help thinking its the coil pack an lead m8 with it just doing it on power

there cheap enough to rtry a new one out though

Motorcycle_Enthusiast · DTR Member

tripr wrote:
I cant help thinking its the coil pack an lead m8 with it just doing it on power
there cheap enough to rtry a new one out though

Well that was my thoughts, but I swapped it with another... altho.. Who knows if that is screwed too? Are all DTR coils the same? YAMBITS say they are, I'm not so sure?

Anyone?

-- Edited by Motorcycle_Enthusiast on Monday 17th of October 2011 08:35:57 PM

-- Edited by Motorcycle_Enthusiast on Monday 17th of October 2011 08:36:54 PM

tripr · Guru

well that kills that idea then . have you had a filddle with the powervalve position at all

i use my other dt pegged still an that i have open about 3quarters for the best performance offroading

yeah you can use alternate coils im sure there is a high end coil out there.

i remember reading it somewhere.

creamsodauk · DTR Respected Member

have you checked compression? what psi are you getting, could be worm rings

Spark plug wise an 8 sounds too low for a full power, 9 is most common in fp dt's but 10's are used in fp rs 125s so maybe try that.

What colour is your plug, this would help us a lot, need to give it a few full throttle runs for a decent colour, give it a clean and take it out for a run and get a pic after.

With a spark plug colour we can determine the issue better, you say it struggles on the power band, does it get past the splutter and then rev on or does it simply refuse to go above? Have you tried getting up too speed in 6th before it splutters then down shifting?

Seiki · Admin

Motorcycle_Enthusiast wrote:
Well it's not the carb, swapped it.
Isn't the cdi.. Swapped that too, just incase.

As for reading through threads I have read a few but the end result isn't allways posted, hence my post!

I will search some more and see! Cheers

-- Edited by Motorcycle_Enthusiast on Monday 17th of October 2011 07:37:48 PM

http://dt125r.activeboard.com/t42043867/dtr-running-problem-part-2/

Seiki · Admin

http://dt125r.activeboard.com/t27246053/bike-not-reving-past-6000-rpm/

Seiki · Admin

http://dt125r.activeboard.com/forum.spark?forumID=66365&p=3&topicID=24190287

Seiki · Admin

http://dt125r.activeboard.com/t27160546/bike-holding-back-and-failing-to-redline/

Seiki · Admin

http://dt125r.activeboard.com/t24468434/bogging-out/

Seiki · Admin

http://dt125r.activeboard.com/t25236480/how-to-find-a-short/

Seiki · Admin

http://dt125r.activeboard.com/t24190287/bike-not-pulling-in-6th/

Seiki · Admin

try a new plug
If its not that then i'd say a carb problem.Usually main jet gets blocked and results in the problems you are having.The higher the gear the more you are labouring the engine and it will splutter earlier.

ECA · DTR Member

Not had time to read this thread and will post more info later when I have, but have you checked the cable going to the temperature sensor in the head. Check for corrosion around the spade connector. Temporarily disconnect it and go for a ride maybe. Back later with more info.

ECA.

Motorcycle_Enthusiast · DTR Member

ECA wrote:
Not had time to read this thread and will post more info later when I have, but have you checked the cable going to the temperature sensor in the head. Check for corrosion around the spade connector. Temporarily disconnect it and go for a ride maybe. Back later with more info.
ECA.

It's an off road bike mate, the sender unit wire isnt connected and is taped up to prevent earthing out.

I had the bike running today and tried richening the mix a little, had it 1 turn out and it seemed to tick over better than 1 1/2 turns, but it still wont hit the power like it should. I've sprayed carb cleaner round all the carb rubbers and airbox and the revs don't pick up so I know there isn't an air leak. I've got a new coil coming so will see if that improves things. Other than that.... Stator plate? Hmmmmmm

ECA · DTR Member

Motorcycle_Enthusiast wrote:
ECA wrote:
Not had time to read this thread and will post more info later when I have, but have you checked the cable going to the temperature sensor in the head. Check for corrosion around the spade connector. Temporarily disconnect it and go for a ride maybe. Back later with more info.
ECA.

It's an off road bike mate, the sender unit wire isnt connected and is taped up to prevent earthing out.
I had the bike running today and tried richening the mix a little, had it 1 turn out and it seemed to tick over better than 1 1/2 turns, but it still wont hit the power like it should. I've sprayed carb cleaner round all the carb rubbers and airbox and the revs don't pick up so I know there isn't an air leak. I've got a new coil coming so will see if that improves things. Other than that.... Stator plate? Hmmmmmm

That's a pretty expensive bike to turn into a purely off-road machine?
Even if it is an off road bike, why not leave the temp sensor cable connected. The ECU rev limits the engine until it knows it's warm enough (to stop you blowing it up). I think the sensor works on resistance so Im not sure it is satisfactory to leave the input floating.
I would think that a lower resistance closer to ground potential would better suited. Ideally, as an educated guess, 500ohm resistor to ground should make the ECU think the engine is at normal temperature though I would need to check the data to make sure.
Have you tried running it without an airfilter for a short time? Contary to the belief that washing them in oil is a good thing, I have found that this can restric the air flow too much.
Also have you checked the exhaust has been de-restricted or isn't blocked.
The bike will run rough at low speeds and tick over because you have pined the Power Valve open so the engine isn't getting any back pressure. Unless you are planning to ride continualy in the power band there is no advantage to holding the power valve open what so ever and you're best to let the servo and ECU do its job.

Motorcycle_Enthusiast · DTR Member

ECA wrote:
Motorcycle_Enthusiast wrote:
ECA wrote:
Not had time to read this thread and will post more info later when I have, but have you checked the cable going to the temperature sensor in the head. Check for corrosion around the spade connector. Temporarily disconnect it and go for a ride maybe. Back later with more info.
ECA.

It's an off road bike mate, the sender unit wire isnt connected and is taped up to prevent earthing out.
I had the bike running today and tried richening the mix a little, had it 1 turn out and it seemed to tick over better than 1 1/2 turns, but it still wont hit the power like it should. I've sprayed carb cleaner round all the carb rubbers and airbox and the revs don't pick up so I know there isn't an air leak. I've got a new coil coming so will see if that improves things. Other than that.... Stator plate? Hmmmmmm

That's a pretty expensive bike to turn into a purely off-road machine?
Even if it is an off road bike, why not leave the temp sensor cable connected. The ECU rev limits the engine until it knows it's warm enough (to stop you blowing it up). I think the sensor works on resistance so Im not sure it is satisfactory to leave the input floating.
I would think that a lower resistance closer to ground potential would better suited. Ideally, as an educated guess, 500ohm resistor to ground should make the ECU think the engine is at normal temperature though I would need to check the data to make sure.
Have you tried running it without an airfilter for a short time? Contary to the belief that washing them in oil is a good thing, I have found that this can restric the air flow too much.
Also have you checked the exhaust has been de-restricted or isn't blocked.
The bike will run rough at low speeds and tick over because you have pined the Power Valve open so the engine isn't getting any back pressure. Unless you are planning to ride continualy in the power band there is no advantage to holding the power valve open what so ever and you're best to let the servo and ECU do its job.

Expensive? nope, it was a stolen recovered bike I was given by the Police!

It did use to run fine but the last few times out off road it has developed this top end guttlessness! I find these Dt's very tempremental, and unless you have a bottomless pocket it's going to be expensive. I'm going to wait till I get my new coil, I am hopeing tomorrow so we will se if that makes any differnece at all.

As for the sender unit to the ecu? NOPE it has nothing to do with it! Look at the wiring diagram. I've had other DTR's and they've minimal looms with just the ignition circuit so it does not affect it at all. DTX 125? Maybe as they only have a red led and no gauge.

NOPE just looked at a DTX Wiring diagram too// The only things in the ignition circuit are:

Magneto CDI
Battery
Fuse
Starter relay
Starter motor
Main switch
C.D.I.
Ignition coil

So that rules that out then!

-- Edited by Motorcycle_Enthusiast on Wednesday 19th of October 2011 06:14:59 PM

xGINCATx · Guru

Okay so how in the world did you get the police to 'give' you a bike?
I thought they would put it up for auction, or since it's recovered and the owner has signed over the log book to the insurance company it's technically theres confuse

Anyways.. Check the wiring,..
My 04 RE had a temperamental problem of it losing the will to rev out.. (didn't splutter just lost power)
Turns out it was a connection block in the loom had burned out..
It was a thick RED wire and all I did to correct it was just clip the wire at either end of the connection box and soldered a piece of wire the same thickness and never had the problem again

The junction box was RED if I remember and it was also under the tank on the left side (I remember because to get it to rev out I had to give my bike a reach around and fiddle with the bundle of wires)

Best of luck

Motorcycle_Enthusiast · DTR Member

xGINCATx wrote:
Okay so how in the world did you get the police to 'give' you a bike?
I thought they would put it up for auction, or since it's recovered and the owner has signed over the log book to the insurance company it's technically theres

Without saying too much... I work loosely with the Police.

(I AM NOT A COPPER)

Technically it would belong to the insurance company, BUT if the Police cannot find the number on it and know damn well it is stolen they can do whatever they like with it. They are not going to start doing all sorts of forensics on a 125 that's isnt worth much are they? These days they are crushing a hell of a lot of bikes, even for no insurance if you dont come and get it back in 14 days!

So thats how I got it, either went to me or the crusher :]

El_Faggo · Forum idiot

I think its the exhaust pipe, unbolt it a bit so that it blows a little and i bet it revs up, it will be loud but I bet it revs ok, sounds like you have an exhaust full of cack and when you rev the motor it isn't letting the gases escape and chokes up forcing exhaust fumes back into the cylinder.