DT125R ARCHIVE

JonnyWiz · DTR Member

2001 DTR125 - Damm 8000rpm Rev Limited! Help

DeeTee · DTR Senior Member

No you dont need to earth it, it is a speed limiter. It is already removed so just tape it up out of the way somewhere.

I suggest you remove your exhaust and check out two things.

1: with the power valve operating pulley aligned with the 4mm blind hole in the cylinder head, check with you finger that the roof of the exhaust port is smooth all the way to the piston. Be careful that the key is removed and stay away from the kickstarter for obvious reasons.

2: Check in the neck of the exhaust to see if the restriction tube has been removed.

JonnyWiz · DTR Member

Thanks irl give that a bash tomorrow,

Investigated the switch a bit more by taking the speedo off tonight, I wasnt sure what taking the reed switch out is actually doing as it is just prized out the back of the speedo? not actually disconnected from anything? what would removing it completely do? (joining the two wired connected to it)

I checked the powervalve and it is properly aligned so will have a look at the exhaust

Could that be limiting the revs though? you hit 8000 and it just jerks and wont go any further, in any gear

DeeTee · DTR Senior Member

JonnyWiz wrote:

Thanks irl give that a bash tomorrow,

Investigated the switch a bit more by taking the speedo off tonight, I wasnt sure what taking the reed switch out is actually doing as it is just prized out the back of the speedo? not actually disconnected from anything? what would removing it completely do? (joining the two wired connected to it)

I checked the powervalve and it is properly aligned so will have a look at the exhaust

Could that be limiting the revs though? you hit 8000 and it just jerks and wont go any further, in any gear

Removing it completely and joining the wires would limit the speed at all speeds not just at 65mph as it is designed to do, if you are in doubt snip through just one wire about 50mm away from the switch not both (thats unnecessary) and tape the ends up.

JonnyWiz · DTR Member

Well yep cutting one wire on the reed switch didn't make any difference, still limited at 8000

The Exhaust looks like it has been cut in the middle and re-welded so looks like that has been districted.

hmm any other ideas on what it could be?

craigbulmer · Guru

http://www.activeboard.com/forum.spark?aBID=66365&p=3&topicID=31675034

Try this ;) Sounds exactly like mine was..

Dickhead · Nonce

mine did this after going of road it turned out the ht cap stored water swaped it for one of them red ones

JonnyWiz · DTR Member

Thanks craig, already checked that and is perfectly alligned :(

craigbulmer · Guru

Okay, i know this sounds stupid, but take the powervalve cover off, slacken the cables right out, take the black plastic pulley off (its abit fiddly to get off), and turn the p/v around with a spanner 180 degrees, put the black plastic pulley back on, adjust it perfect, and try that

JonnyWiz · DTR Member

Right Update...

Today I fitted a 2nd Hand DEP Full system that I had Brought, didnt notice much of a performance upgrade apart from hitting the rev limiter a bit sooner! (I think most of their performance is in the high rev range though that I cant reach!)

Just slackened off the powervalve and rotated it 180 degrees (there is a little dot on the plate, this was now facing down) took it for a trip and just lacked a bit of performance and wouldnt rev very high think the rev limiter came in a bit early at 7000, so dont think it was that! just gonna change it back

What else can I check? seems so silly! but be an electronic restrictor somewhere surly if it is so precise?

RudiRulez · DTR Senior Member

new air filter?, mine was being limited up in the high revs because my airbox was filled with popcorn kernals that a mouse had stashed there whilst it was in a garage for a few years, so i cleaned them all out and replaced the air filter now it revs freely.

if u reckon its an electronic limiter u might be best off heading over to the german dt site as they have derestriction guides for all of the electronic restrictions, just one little problem all the guides are in german.

http://dt125.com/ <<go there, click 'werkstatt' at the top, then click 'Entdrosselung' on the right, then all down the right theres links on how to derestrict different electronic restrictions and a few other restrictions.

-- Edited by RudiRulez on Saturday 12th of June 2010 04:43:32 PM

JonnyWiz · DTR Member

Thanks Rudi, The Air filter looks brand new, should i go for a test without it in to see if it restriction or will that do damage?

I have checked out dt125.com unfortunately google translate is not the best on their guides! but have posted in their form to see if anyone there has any idea

DeeTee · DTR Senior Member

When you had the pV pulley off what did you see...was the end of the PV a diamond shape?

JonnyWiz · DTR Member

Heres the powervalve, did you mean behind that (the thing that the black piece fits onto)? I was just sort of rectangular with round corners, dont think it was massively diamondshaped

There are a few guides on that dt125.com about electronic throttles etc but they don't translate well so cant try them (and also dont say what year they are for)

How much should the powervalve move when your turn the ignition on, mine rotates clockwise about 90degrees or so and then back,

So to sum up..

White reed switch taken out the back of the speedo

DEP Exhaust on,

Powervalve perfectly alligned, also tried turning it 180 degrees

Air filter is virtually new,

-- Edited by JonnyWiz on Sunday 13th of June 2010 09:24:08 AM

JonnyWiz · DTR Member

I have just had a look at the powervalve when the bike is running,

this pic is when the engine is ticking over and it moves a bit clockwise when I rev it, (didnt move a lot though, but didnt rev too high, then it falls back to the pictures position

Is this correct?

EDIT - err going by this mine turns the wrong way when I rev? lol

http://www.youtube.com/watch?v=UX2yOcv2lf0

and this

http://www.youtube.com/watch?v=-4Xhmw5zIi4

-- Edited by JonnyWiz on Sunday 13th of June 2010 09:37:30 AM

DeeTee · DTR Senior Member

Rectangular with round corners is ok, there is also one with a diamond shape fitting but that doesnt apply to you....so yours is either bang on or 180 degress out depending how you fit it.

A mate of mine has a DTRE and his PV turned the wrong way too, only thing is he didnt have a tacho so couldnt see how it revved...I dont know what the answer is as to one that rotates the wrong way!! if it were me I would be considering crossing the drive cables if they are long enough but perhaps theres another explanation,
is your bike one of those that have a green'black wire that needs grounding?

JonnyWiz · DTR Member

yeah am playing with the cables at the moment but don't think they are long enough, may have to take the tank off to get at the servo motor bit that drives the cables

Nah mine is 2001, it doesn't have the cable that needs to be grounded (as far as i can tell through my research) just the white reed switch

plebpl · Guru

take your carb off and give it a good clean through, could be lack of air / lack of fuel. if not you got a nice new clean carb anyway :D

woll · Guru

Check the cables are in the right holes, iirc number one wire on the pully goes into number two hole on the servo and the opposite for the other wire. So they cross over between the pulley and the servo. That might why it turns they wrong way, it does say in the haynes which way round they go but i've lost my haynes so i couldn't tell you,

JonnyWiz · DTR Member

Researched the cables a bit more now, wouldn't swop over, (yep on my year bike, cable 1 form the servo goes to hole 2 on the valve! (they do not cross over)

After further inspection of the powervalve whilst running it moves slightly the wrong way (clockwise) in the lower rev range but then does come back the correct way to line up when rev'ed hard, its just the random movement when idling/ low revs is a bit weird,

Its not like the bike lacks any performance its quick just cant get past about 7500rpm!

woll · Guru

yeh thats what i meant lol

JonnyWiz · DTR Member

Today I put the white reed switch in the back of the speedo, it didnt seem to make any difference? As it had been removed when i brought the bike i am thinking that perhaps someone has tampered with it whilst trying to disconnect it and buggered it up?

possibility? running outta things to check, the carb is clean and fine

plebpl · Guru

when you move the reed switch tape it up and make sure its well out of the way

woll · Guru

coked up zorst?

JonnyWiz · DTR Member

Nah the exhaust isn't the problem as had the limiter with the old exhaust on or my new DEP full system,

plebpl - i will remove the switch and tape it up again and see if i can notice a difference but i dont think it is deactivating the limiter like it is supposed to going buy all the guides

One question - my power valve is perfectly aligned with the cover off etc.. but could it still be wrong inside the engine? (by taking off the exhaust and checking up the err hole? (lol sorry thats where my technical knowledge stops). what shout I check for exactly?

fray · Guru

@ woll. It was the same with his old exhaust and the dep he has on now.

@ jonnywiz. It sounds to me like a problem my mate had on his rs125. It wouldnt rev above 8,000rpm. He fitted the correct main jet in the carb and it fixed the problem. It turned out the main jet was too big and it was running way too rich at top end of revs so just bogged down.

JonnyWiz · DTR Member

Thanks fray.. im not too clued up on carbs, my mate had his off the other day thought so can rope him in, What exactly should i be checking for?

I do seem to use a bit of petrol, would this be a sympton? however the tank is tiny so maybe just that lol

-- Edited by JonnyWiz on Monday 14th of June 2010 08:34:19 PM

DeeTee · DTR Senior Member

JonnyWiz wrote:

One question - my power valve is perfectly aligned with the cover off etc.. but could it still be wrong inside the engine? (by taking off the exhaust and checking up the err hole? (lol sorry thats where my technical knowledge stops). what shout I check for exactly?

You already said your PV is the type with the rectangular pulley mounting, this means your PV will be either correct or 180 degrees out. If it was 180 degrees out it would appear as a sleeping policeman in the top of the exhaust port and would have the same effect. I doubt it but next time you have the exhaust off check the top of the port is smooth when the pulley slot and hole are aligned.

Dickhead · Nonce

ther is a dot on the pv you need to make sure its facing the 4mm hole when you put on the black pully

JonnyWiz · DTR Member

Thanks guys, the dot on the Powervalve is facing up and correct,

I shall take of the exhaust and check to see if I can feel anything up there

Also going to take the carb off and try changing the main jet? (dont know a lot about carb's) What would you suggest changing it to?