DT125R ARCHIVE

Spartan · DTR Senior Member

HT Leads

woll · Guru

The ingnition coil makes the spark for the spark plug, the ht lead takes the spark from the coil then cap then fits on your spark plug and the spark plug sparks and ignites the fuel making the bike run :).
Yes the fuel tank does need removing to inspect it as the coil is bolted to the frame under the tank, the fins are on the side of the coil that bolts to the bike if they get a bit rusty then it won't earth properly and the bike will run dodgy as i found out.
And the reason you chop the lead back if there is no copper in the end is because it makes a better connection ( if there's no copper then there will be a poor connection and the bike will run dodgy)
Hope that helps

Spartan · DTR Senior Member

Thanks Woll I understand now smile

I've just taken mine out:

The fins and bolts are pretty rusty and there is another bit where a white connector block (orange wire going in) slips onto and that looks pretty corroded. To clean this up am i ok to use WD40 - as long as i remove it all afterwards, and a wire brush?

Cheers mate

Seiki · Admin

yup same thing i used , works a treat

Spartan · DTR Senior Member

Cheers Seiki will get that done. Didn't ask before but which bit do i check for copper to see if it needs cutting back, and one more thing haha, does the cap seperate from the lead?

.... · Guru

the copper part is in behind the cap, undo the cap from the cable turning anti clockwise, check the cable see if any copper, if not chop a bit of end, screw the cap back on clockwise then done

also if your using wd40(no advised from me) make sure its all rubbed off,

the orange wire that attaches to ht is the live spark wire

the black wire that goes to it is the earth

make sure all the contacts are clean from rust or currosion

woll · Guru

my bad should of said you unscrew the ht cap and if you can see plenty of copper wire at the end of the lead after you've taken the cap off then it doesn't need cutting if however there's only a few wires then cut it back a few mm with some pliers

ps i just used 0000 grade wire wool nothing else wd40 is flammable and the ht lead carries a spark so it could ignite and start a fire and then the fuel tanks above it so there would be a big bang ;)

-- Edited by woll on Sunday 21st of February 2010 01:33:30 PM

Spartan · DTR Senior Member

Ok got it off and loads of copper strands fell out, i can see now where it needs to be cut back. Does the copper actually need to be sticking out of the end? Looking down the hole of the cap there is a small metal contact plate which i assume touches the end of the spark plug. This doesn't look in great condition either, abit corroded in fact. Can i remove this out of the cap or does the cap need to be replaced. Thanks biggrin

.... · Guru

yeh screw the cap so that the screw is touching the copper, replacement caps are £2-3 probably worth replacing to be fair

or the whole coil maybe?? they only £20 odd new

woll · Guru

dont go ott if you haven't got problems i wouldn't change it :) just litteraly get the plier and cut a few mm off each time until you see a lot of copper inside the ht lead then its done

gaz beat me too it again lol

-- Edited by woll on Sunday 21st of February 2010 02:18:38 PM

.... · Guru

of course dont spend money if it works lol

Spartan · DTR Senior Member

Done, cut back and i can now see plenty of them. Well actually, yesterday my bike refused to start first time, has been doing it more so lately and takes maybe 5 or 6 goes of pressing the starter switch which is when i thought it could it be the spark plug, now i'm thinking it's the lead after inspecting it and reading a few threads on here. Here is my plug too:

I think it's ok - it has a brown tan.

.... · Guru

brown tan is perfect

Spartan · DTR Senior Member

Nice don't need to replace that then, this should be ok i'm thinking:

http://cgi.ebay.co.uk/Reliable-SPARK-PLUG-CAP-for-YAMAHA-125-NXC-CYGNUS-NGK_W0QQitemZ190364916418QQcmdZViewItemQQptZUK_Motorcycle_Parts?hash=item2c52a21ac2

craigbulmer · Guru

i was thinking the same m8.
mines about 15k miles and its never been touched lol and the cap wont separate

Spartan · DTR Senior Member

I thought mine wasn't seperating at first but just keep twisting it, on mine is a rubber sleeve which you can peel back it's alot easier then, i found this out after lol:

Spartan · DTR Senior Member

hey guys, just got home and decided to fit me new NKG plug cap, only thing is it will not sit tight on top of the spark plug, it's very loose and not making contact. Any suggestions? The spark plug is NKG br9es.

Cheers.

.... · Guru

on top of your spark plug it has a nipple, remove it anticlockwise

Spartan · DTR Senior Member

Legend Crazy!!! Fits prefectly now. Now that i have done all of that, bike now starts first time every time and ticks over so much better now, well chuffed :)

craigbulmer · Guru

why would you need to remove the nipple on the top?

was inspecting mine with a torch earlier, connectors inside are all rusted up, will order a new one me thinks.

Spartan · DTR Senior Member

I found that the nipple on top of the spark was too wide to fit into the metal holding of the plug cap. I did not know this could be unscrewed at first but it now fits all the way into the cap with some reassuring clicks and is secure.

Mine was the same and was actually some how broken inside, the link i pasted above is where i got mine from, so much better than the standard plug, get one craig :)

-- Edited by Spartan on Saturday 27th of February 2010 02:21:37 PM

.... · Guru

you dont need to remove it craig, the little fitment on top of spark plugs are so that you can use multiple plug cap sizes and will still fit snugg

-- Edited by DTR125CRAZY on Saturday 27th of February 2010 03:48:31 PM

frogboy · DTR Senior Member

Hello, just hi-jacking this thread as i don't want to start a new one for what could be a quick solution...

So i bought a NGK cap, removed the tank and took this off....

i've pulled the cap off (without unscrewing

) literally and am not sure if i need to cut back the rubber tube/ht lead or just screw the new NGK one straight into the hole ?

Also can anyone tell me what these two plugs should be for (shown in photo below) i found them unplugged after removing the tank.....

.......

please help

thanksyou

frogboy

.................. wink

p.s. when i unscrew the nipple on the spark plug to alow the NGK cap to fit snug, is it the metal thing at the top of the spark plug and can i do it without removing from engine, also what do i use to unscrew the nipple so i dont damage it ???

-- Edited by frogboy on Saturday 6th of March 2010 05:21:44 PM

-- Edited by frogboy on Sunday 7th of March 2010 12:47:07 PM

woll · Guru

Best way to tell is to look down the ht lead nd if you can see plenty of copper close to the edge of the lead then its fine if not cut it back until there is a lot close to the end of the lead. from what i can see of your lead i would say it could do with cutting back. And the nipple should just unscrew if you cant do it by hand use a pair of pliers, and if that ht cap doesn't fit with the nipple on dont worry about damaging it ;) not a clue what the wires are for though sorry

frogboy · DTR Senior Member

Cheers woll

woll · Guru

no problems mate if you;ve got msn send me your addy on pm n ill add you, can give you help quicker that way ;)

frogboy · DTR Senior Member

msn ? not at the moment, will look into it think i used to have an account years back when i worked abroad.... confuse

Spartan · DTR Senior Member

Whoa i thought i was the only one here who hijacked threads haha wink

Hey bud just thought i'd mention that there are some wires disconnected on mine too, i didn't bother tracing them at the time but i'm thinking they could be spares?? Everything works as normal though.

craigbulmer · Guru

not unless its off an RD with multiple powervalves haha ...

its a DTX m8 its already plugged in

frogboy · DTR Senior Member

Maybe there for pluging a turbo in ?? LMAO