DT125R FORUM

I had exactly the same problem on my old DT, its because i decided to fill it up with magnatec oil which is used to hold to components so they are covered in oil before starting, however this is useless in a wet clutch bike, even with new oil they still stuck, so i removed them all, cleaned them in paraffin along with the pressure plates and spring, and then dried and coated them in new oil. i think i even changed the clutch springs because they were slightly under tolerance and only £10 or something.

this worked perfectly and i only ever ran the bike on halfords special oil from then on as thats what it was happiest on.

I think i saw this bike advertised on facebook, should be a great bike when finished, i contemplated picking it up

I have always used this stuff and it hasn't let me down yet
Castrol Power 1 2t, its usually £25 a liter but you can always find it cheaper on amazon

https://www.amazon.co.uk/Castrol-Power-Racing-Engine-Oil/dp/B004I5R35S/ref=sr_1_1?ie=UTF8&qid=1466763110&sr=8-1&keywords=power+1+2t

Its all apart now, plates were cleaned with paraffin and are soaking in the oil i will be using, they have loads of meat left on them so they should be fine, should i put the metal plates and ring in the oil as well?

basket and cage are good, however the springs weren't, 2 mm below Haynes serviceable limit, will order a new set soon,

when i removed it they were literally glued together, my fault really, should have disassembled and cleaned before putting in but i was just lazy.

will keep you all updated

@Uber_Beluga

@Calum said in Setting up the PowerValve:

Sounds like powervalve to.me.

Quick test to see if it is.

Take the exhaust off.

Using the adjusting screws on the side of the engine. Move the powervalve so that it is flush with the exhaust port.

Then disconnect the valve and test the bike. Should be low on power till around 6k where it will pick up right to the red line. If so voila, the powervalve needs setting up.

Easy enough job.

When you turn the ignition on, the powervalve iterates through a cleaning cycle where it will.go to max open and max close.

By using fingers up the exhaust port. Turn the ignition on and off and feel how the powervalve sits. Adjust to a point where the valve turns to max open, and is flush with the port.

This should line up with a mark underneath the powervalve cover. Although I prefer to feel how flush it is.

Can anyone link me to calums guide for rebuilding the clutch?, i cant find it anywhere.

Hi only me again,

today has been up and down for me,

basically ive had an engine lying around for ages, all seemed in working order so after finally reassembling it (just the top end and clutch) i decided to put it into my bike to see it it starts.

low and behold it started on the second kick !

engines running sweet as it could apart from a weird clutch problem i have never experienced.

the clutch drags really bad, the cable is fully adjusted on the bars and the adjuster and it still drags?, most of the time it will just stall if the top adjuster is not at its maximum.

i refitted the whole clutch, which had been used before (it did not look worn at all), including the part with the gear on.

everything was alligned correctly, im sure of that 100%, apart from maybe the clutch plates, could that be causing the problem?

also the rod and ball bearing were inserted in the correct orientation and order too.

the adjuster on the clutch also had to be adjusted so the locking nut is barely biting the shaft so that the part where the cable attaches is aligned with the little notch.

any help would be appreciated

A new OEM clutch cable has been ordered as well, thinking that may be the problem as the cable should not be fully adjusted anyway.

ill try different oil first and see if that helps.
any recommendations on which one to get?
im finding it hard to find any deceit 10w30 oil to run the engine with?

The Leak has been fixed!,

it was the clutch gasket after all, it had split and some of it was inside the casing.
put on a new Athena gasket and its all okay now.

however a few more problems have arisen now and i dont know where to start.
firstly my clutch is slipping a lot more now and it probably has to be replaced which i dont mind doing. this may be the oil i am using (Castrol magnatec 10w40), i saw a post ages ago with someone having the same problem.

however the main thing is now the kick-start sometimes does not engage when it is kicked and the bike has to be rocked for it to work again.

if im not mistaken this is also because of the clutch?

regardless of the kick start problem, i have to disassemble it again soon for a clutch rebuild,

does anyone have any suggestions on a clutch kit?, and a bolt kit for it as the ones i have now are not too great. and maybe some advice on the kick start problem?

thanks

Alfie

Also i saw someone offering to rebuild engines a while ago on this or the old forum and i cant seem to find it?,

It might have been you calum

Im not looking for the service, just what you were offering so i can do it myself?

Any help would be appreciated

I dont think thats its the drain bolt, it sheared when doing an oil change and i had it re-tapped and a new bolt put in, it does go in at a wierd angle but its not leaking.

I will have another check though in case i was wrong. If it is i just got another supposidly running engine for £71!, if that dosent work then ill have to rebuild another one that i have.

Hopefully its not that bad and changing the clutch gasket will do it

About a week ago i started having an oil leak from the engine somewhere, defiantly engine oil.

i did think it was fuel at first but that has now been ruled out.

anyway. so far i have replaced the fuel tap (old one was rusty and hard to turn), going to replace the fuel line to the carb and the 2t oil line then bleed the oil pump ect to rule those out too.

i have also brought a new clutch gasket to see if thats the cause.

if its not has anyone got any idea what it could be?,

there was no rough riding or anything like that so i have no clue?

@Calum i have them sketched out already i think the centers of the holes are 85mm apart for a 25mm rise?, i need to find some thicker metal somewhere aswell maybe stainless steel to, that would be stronger

@Calum
its all working as it should now, the bike is also 2001 the plate is a private one haha, still need to adjust the mixture a bit but ill wait for it to be dry for that

thankyou
spark was great and arc'd to the frame even, it was another case of a dodgy plug, even though it seemed to work it didnt, i replaced it with an old iridium br9iex and it started fine first kick, bit rich but thats sorted now, and it kept a steady idle for about 10 mins without choke.

it threw out loads of rubish from the end can though, i guess this was what was left after all the failed attempted kicks.

anyway ill keep you all updated

So, here we go

I brought a DTR last September and it was a brilliant bike for about a month then all of the problems started comming, they were all pretty much fueling related and i had no clue what was going on, each part in the carb was dying 1 by 1. then the powervalve pulley and cables broke. anyway, the fix

first i brought a new power valve pulley and cables because the old pulley had snapped and the cable frayed.

also ended up picking myself up a new carb, apparently from a running bike so that i can use the bike and repair the original carb at the same time.

however this is what turned up, a carb from the older dt's i think, anyway i ordered another one that was the right one, little bit of repaired damaged, stunk of fuel tho so thats always a good sign.

i also got a reed block spacer and some new hytech fibre reeds, not sure if my problems were caused by the old ones but new ones cant hurt, right?. the inlet manifold was also changed because some idiot in the past had cut the funnel bit out that directs the air and fuel mix, which may have also been causing my problems.

so next up was to fit it all, my mum wasn't happy about this but because of the weather down here it had to be done, welcome to my kitchen turned garage

so the next bit was simple, all i had to do was re assemble it all. which at this point was easy as it had been in bits so many times before. Starting with the Reeds, Manifold and Spacer. also a few home made gaskets were added, these were a pain to make to because they had to be so thin.

next was the carb and the boost bottle, these fitted straight in like this. the hard bit though was trying to refit the air box, even with out the spacer this is still a job getting in, anyway eventually it went in and the bike was put back together.

So did it work, sort of, the main jet was a 240 in the new carb and it looked pretty good inside, it ran for like 5 mins the just wouldn't start again, did a plug check and it was covered it fuel, so ill try making it leaner today, so i guess the mixture screw is done up to do that???

Also on a side note has anyone ever made their own dogbones for the suspension, i did a first attempt at work yesterday out of 5mm lcs and its defiantly not strong or thick enough to do the job, just wondering what other people used. the plans were of someone on this website (obviously i didn't finish them because i knew they wouldn't work. not the plans the metal used)

Any more suggestions on what to do would be great.

@Calum
It was the carb that was the problem, along with the valve, i will order new cables and pulley soon and see if thats it because the cables are frayed and pulley bends when being moved.

the carb just gave out on me today, last month it was set up professionally, and fixed after my previous troubles.

after a week i did a plug test and it was perfect

however, even though i rarely ever use the choke, even to start it, today it just stopped working entirely.

i did a plug check and it was completely fouled, so a new one was tried and it still wont start. (it did for a bit but idling really high)

i have no clue where to begin, any help would be appreicated

thanks

Alfie

@Calum ive done what you said, i disconnected the servo and pegged the valve open, bands at about 7-8k now which is what it should, did a speed run aswell and got it to 60 now, then i think the carb gives up.

I may try upping the jet size to a 240/250 rather than the 210 thats in there now as i have a full dep too

If that dosent fix it then ill probally do a carb swap with another one

Got a new set of cables and a new pulley comming too so ill see if that helps

thankyou for replying, depending on the weather tomorrow ill do it then

Hi

I have a 2001 DT125r and it hasent really been running right since i got it, its all fixed up now.

anyways ive been looking everywhere for the best way to set up the powervalve, im sure that is what is causing it to not rev right through the range and throttle itself at around 6k -8k revs, the reed valve is removed so i dont think its that.

at the moment there is no band either and still stops going any higher at 6-8k in every gear.

any help would really be appreciated as its getting to the point where i dont even want to ride it as im stuck at 50mph on A roads.

Alfie