DT125R FORUM

@markus-w thanks mate, i'll certainly give that a try! Cheers.

@Calum yes certainly is a pain to work out whats wrong! Knew others would have had similar issues! Cheers mate.

Hi all,

Rebuilt my bike (3RN I believe). I came to kicking it over and it wouldn't start. Removed spark plug and tested for a spark. It didn't. However, after testing for a spark i turned the kill switch from 'on' to 'off' and as it toggled the spark plug zapped me. Therefore, somewhere my wiring must be wrong. Did this twice and confirmed it only powers the spark plug when toggling the kill switch after kicking over. The bike is purely kick start. See below.

The bike is no longer road worthy and it was converted to an off road bike by the previous owner. Therefore; speedo, ignition, lights, battery, stand etc etc are removed. As a result, most of the cables on the CDI unit have been previously cut and taped up.

The only cables used on the CDI:
Orange (to HT coil)
Black (earth)
Green and white (stator)
Black and red (stator)
White and red (stator)
Black and white (kill switch)
Light blue (currently going to earth)

The following cables are not used:
Black and yellow (no idea)
Blue and yellow (cut - should be side stand i think)
Blue (cut - should be neutral lamp i think)

My questions are:

What does the sky blue cable do? Should it be going to ground (considering the systems that aren't on the bike now)?

One cable going from the stator to the CDI begins life as a white and blue cable. It then goes to a joint and turns to a black cable. Should this black cable join to the other black earth cables? The wiring diagram in the Haynes manual (page 173) shows the colour change is correct, and also shows 2 black cables for the CDI but my CDI only has 1. I currently assume all black cables are to earth and have wired it as such. Is this correct?

What is the purpose of the black and yellow cable? I cannot tell from the wiring diagram in the Haynes manual. I remade the wiring loom myself (by copying the previous cable) because it was in a bad state, and have (probably incorrectly) connected the black and white cable from the kill switch to the black and yellow cable on the CDI (from memory the previous owner had done this). Now I have checked The Haynes manual it shows black and white should go to black and white on the CDI so I plan on making this change. Without knowing what the black and yellow cable does I am not 100% that this is the problem. (Although it is the most likely issue).

Any help or comments will be very much appreciated. Attempted to attach the haynes diagram and a picture of the CDI but my phone won't allow it.

Many thanks in advance everyone! Appreciate its long winded but feel it needed to be!

Cheers.

Thanks mate.

All makes sense, so i can fix the flywheel on in any position and it'll be okay?

Thanks mate, so when those dots are aligned its in top dead centre!? I've already rebuilt the gear box so know that part is okay .

(Ive not got the top end on at the minute)

Thanks Calum, I'm a bit rubbish with the accurate stuff. Is top dead centre when the crank is extended to the full? Or just off?

I've fitted the stator plate (rebuilding the engine) and didn't mark it... as far as I'm aware it can only really go in one position anyway? When putting the flywheel onto the plate, is there a position the crank needs to be in? Ie should the woodruff key be pointing in a particular direction? Worried about getting the timing wrong, as i rebuilt the engine last month and on kicking it over blew the seals when i turned the kill switch off (anyone any ideas on that to?).

Cheers.

@DTR-NSR thanks! checking for a spark will be next on the cards! If theres no spark does anyone know the most likely causes? Or is that a stupid question? Guess theres plenty of reasons for not getting a spark?

@Calum I'll look into it once this bloody bike runs! Cheers mate

@Calum So a 97 dtr can be fitted with a servo? Bit confused mate haha

@DTR-NSR ok, definitely possible and sounds like it could be the case! I'll have a look

@NINJA Thanks fir the tip mate, yeah think the seal is now damaged, but think the damage was caused as a result of the sudden high pressure build up, as apposed to me damaging it on assembly. Cheers for the pointers

@Calum my dtr doesnt have a servo style powervalve, it has the old style where you set it how you want it. Therefore dont think the ignition would move it. I agree the switch shouldnt have any effect on the dump noise but it deffo did. Bit weird, hence why i think i might have wired it up wrong somehow

The main concern is that it wont turn over, and that pressure (pressure that i dont think should be there?) is dumped when the on/off switch is turned to off.

@finnerz89 yeah, but it shouldnt stop the engine starting should it? So confused now haha.

No! Which i then realised, so when i tried it again i did have it off. Although that might have caused the leak initially i still dont think it explain the dumping noise and lack of ignition? Any ideas? Thanks for your help.

Hi, looking for some advice...

I rebuilt my bottom end and have put it back in the frame, connected electrics and put coolant in the radiator. I just tried kicking it over (about 10 kicks) and nothing happened. I then turned the on/off switch from on to off, and all of a sudden the bike released a load of pressure, it sounded like a dump valve. Did it once more (only a couple of kicks) to see if it was a fluke, and it happened again. To add insult to injury my coolant is now drip leaking from the crank sealant. Has anyone got any idea what might cause thise to happen or how to rectify it? Could wiring it up wrong have caused this?

Thanks
James

Yeah not sure why, ive seen 2nd hand cases labelled 3BN 00, 01 and 02. Maybe its the place of manufacture, or just subtle changes in materials or something? Ive noticed the 00 case has a couple of shallower indents on the outside of the case, and a couple of radius corners are subtly different. Could be a different manufacturer