KevShek

All sorted now. Turned out to be the live wire on the ignition barrel. The connector has 4 wires, and the live crimp had completely corroded away! so ive bypassed it and put on a new connection. Job done.

Hi All, My DTR has sudden developed an electrical fault. Usually, when you turn the key, the neutral light will come on, and youll hear the power valve reset. Only now, no light, and no movement from the valve. The first sign of trouble i had was after starting the bike normally, then as i rode home, the indicators did not work, although my front/rear and brake lights were still working. Nearer home, the indicators started working fine. When i got in, i decided to check it out, and noticed that when i turned the ignition on, the neutral light either flickered or comes on after a delay, like there was a bad connection. This cause the relay under the rear mudguard to flick on/off rapidly, and also the valve to go a bit crazy. Ive checked the relay (which i dont know what it is) and even with that disconnected, the neutral/ign was still going on/off. Now it just wont turn on at all. Ive checked the battery which is fine. There is a fuse i installed right next to the battery as there wasnt one when i got the bike, that is also fine. Is there any other fuses on the bike or does anyone have any suggestions on what to check?

You could try Q-Bond, have a look in your local motorfactors, the kit comes with 2 powders, grey for aluminium and black for plastics. Its meant o stick anything to anything and oil resistant, not 100% sure for petrol thou but its worth a try, its about £12 quid a kit.

Yeah, im gonna check with the bike shop tomorow. Ive printed off the pics and have marked the parts i need and have faxed it to them, ill ring up and get him to compare it with their system. Im basically gonna buy whatever clips/spacers are on either side of that spur gear, in other words, No.3, 4, and 5 if they all exists on my model.

Thanks for that, now you mention it, when i first investigated this, i took the cover off and found a piece of a spring clip, semi circle at the bottom of the crank case. Also, the spur gear does come off the back of that shaft. Judging from the diagram, the clip no.3 should be the last thing on that shaft right? in where the groove is, so therefore, it would retain the spur right? Thats what i need, THANKS!

I've looked, and can't see anything, but the manual is a photocopy and some of the pics are great. Will look into it again

One final problem I need to sort out. The kick start won't engage first time. I've had the cover off and hav e check the shaft, gear, spur gear and spring which all seem to be fine. The kick lever returns back to the top so I know the spring is working. What I have to do is flick the kick start a few times by hand, once I feel it engage, then I have to keep pressure on it, place my foot onto it then kick the bike over. Is there something that's worn or missing that would cause the start not to engage? The spur gear does slide back and forth on the end of the shaft, but I don't know what's supposed to move it into position. Can anyone help?

WOW man! what a difference! The bike just pulls and pulls! theres no hesitation into the powerband now, its smooth and the power is emence! It even pulls well in 6th gear now. So that all it was all along, plus the speedo wires. Thanks for the tips.

Well, after you mentioned the PV, i decided to take a closer look at it. According to the workshop manual, after youve turned on the ignition, the keyway is meant to line up with the hole behind it, well, min didnt! After a bit of adjustment on the cables, and looking up the exhaust port, ive reset the cables and now it lines up on ignition. Gonna take a ride out and see how she goes now.

How do I go about cleaning the power valve? Tbh I don't know what's been done to the power valve, I don't even know how many previous owners its had! I'm still waiting for my V5 doc. I do know the last owner disconnected the plug to the PV servo thou, and left it open. I've since reconnected it all up. I have seen the write up on adjusting the PV on dtr.net thou, it looks linda scarey but I'm willing to give it a go. Can you tell me how much rotation the valve has from closed to open? I've looked at the servo motor and that rotates about 90 degrees when I turn on the ignition. Is that all its supposed to move? Obviously that 90 degree then translate through the cables onto the PV itself. I guess ill have to take the exhaust off and see how much it moves and if it fully opens. Should it fully open and then close when I just turn the ignition on? I've noticed while riding, as I'm approaching 7k rpm, it seems to struggle past into the powerband, especially in the higher gears and if there's a head on wind. Thanks for you help.

Mine a W reg 2000 year. Well, today i stuck a couple of crimp connectors on those 2 wire and decded to try connecting them. It sems to be working, so my guess is im just gonna leave them connected. It will now go over 60 mph, but i do sometimes need to drop down agear as the powerband doesnt respond well in 6th gear from 7k rpm, ive gotta change up a bit later in 5th to keep it going. Anyways, it passed the MOT today and the bike is taxed so im all good to go.

Ive been reading up,these 2 wires may have went to a reed switch inside the clock, but its no longer there, on the DT.net website, itsays not to cut or disconnect them, but theres nothing the now. Should these wires be connected? are they joined internall in the reed switch and then the circuit cut when it hits 60 mph?

Behind the speedo, there are 4 wires. Blue and black go into the speedo and goto the bulb, however the black/white and red/blue wires dont go anywhere. They are just stick up into fresh air! they dont look as if they connect anywhere, i.e. the end have been cut clean (not frayed)and there are no connections inside the speedo for them. What are they for?

Hi all, ive just got my DT back on the road. I recently bough a 2000 year model which has had the reed valves done, and an exhaust. When accelerating, it fine and goes no problem, but when i change up into 6th gear, the bike no longer pulls in the power band and begins to slow. If i drop it down to 5th, i can pull away upto 100 kph, but as soon as i got into 6th, it starts dropping speed to 60-80 kph. I feels as if its bogging down. Any ides?

Thanks for the help. Ive removed the kickstart shaft and the spring has snapped, so i guess i need a new shaft. Ive found what looks like a small nipple where the carb is, just after the air box. I guess thats where the small tube goes. Has anyone got a workshop manual for the bike?

Hi all, Ive just aquried a DT125R which needs some work done. Can anyone help with the following. 1) Ive been told that the 2 stroke bottle hasnt been mixing as the bike felt sluggish, the previous decided to premix. Ive stripped it down and found a small black tube disconnected next to the crank case where the 2 stroke bottle goes into. Does this tube fit anywhere? if so where? 2)Ive also noticed a disconnected plug, this seems to go to a cable controlled unit which is fitted onto the head, i believe its got something to do with the power valve. Can this remain disconnected? 3) Finally, the kick start isnt engaging unless you flick the arm over a few times, what do i need to check? Thanks, kevin

Thanks for the tip, luckily, my speedo uses an electronic sensor on the front wheel, so whatever the back wheel is pushing me along at, it will remain correct.

thanks!

My 125 currently uses a 14T front and 48T rear sprocket, and id like to change them to gain some top speed. How do i calculate what tooth sprockets i can go for?

Heres some pics Big bore kit 60mm this kit includes -167cc big bore 60mm ( high quality ) -60mm piston ( high quality ) -Piston Ring -Piston Pin -Stage 1 Camshaft to suit the big bore kit -Base Gasket -Top Gasket Big bore kit 57mm this kit includes -150cc big bore 57mm DiASil Cylinder -57mm piston Forged Piston -Piston Ring -Piston Pin -Stage 1 Camshaft to suit the bore kit / Stock Camshaft -Base Gasket -Top Gasket Also Stage 1 Stage 2 Stage 3 cams available

Here you go, for the people interested in gaining some more power from their R125, you can get an increase in power by fitting a larger cc piston kit. These kits will be arriving in the UK shortly. http://www.yamahar125.com/forum/viewtopic.php?f=3&t=113 Tech info will be available to buyers who want to diy it.

Would many of yous be interested in the 150cc kits for the yzf r125? Im looking to get together with someone in India who may also be able to supply these kits. All parts will be genuine Yamaha bits, as they produce the R15 for that country. What i know so far is that the R15 and R125 are basically the same except the cc of the engine. This kit would be a straight swap, cylinder sleeve, piston, pin, clips and gasket. As the ECU and head/cams are the same too, there wont be any other issues to deal with. Prices will be around the 250 mark or cheaper depending on what deal i can get, and what numbers are involved. This is cheaper tha buying most performance exhausts and would gain you more power, simply because, the bigger the cc, the more power it will make. If youre interested, rop me a PM just to let me know. There is no ETA for these at the moment, so you ont have to rush it, but there should be a few kits heading into the UK i the next few weeks. I will hopefully be installing one, and doing a writeup for it.

yeah, i know the seller too, ill be getting mine at the end of the month

found a site more specific to the r125 Clicky!

The things ive tried have helped, but i wouldnt says its a big gain. I dont think you will get any huge gains unless you go bigger cc. There are 150 and 170 cc kits out there, but its down to how big your pocket is. The mods ive done have been on the cheap, which i dont mind, and ive already decided to keep my bike for a while, 1, as its financed, and 2, as my eldest will be 17 in a few years time. You could change the gearing of the sprockets, but by gaining acceleration, youll loose top end, and trust me, you dont want that, cos it aint that fast to begin with.