DT125R FORUM

@SpookDog

Fixed it!!!

So airscrew didn’t have a o ring so put one in.
Also when I was checking air leaks nothing, so I thought I’d take carb out and check all rubbers, where the jubliee clip tightens up onto the carb on inlet there was a hairline crack under the clip which I only saw when I flexed it about. so put the carb back on and sprayed like 2mm away from the place I saw the crack and sure thing revved up. So that’s why I didn’t rev before when I sprayed because I had to be really really close to it!

After all that I’m glad though crazy how a tiny tiny little crack can do that but where it was hidden under the clip it didn’t pick up the brake cleaner until really close.

Thank you everyone been a couple of stressful days but that’s a win and learn something on the way

@DTTOLATE

Looks smart I do love custom bits my brother made me some of these chain adjusters
So much nicer than the OEM steel ones
What do you think?

@SpookDog
2.5 cutaway slide
Also brand new oem throttle cable it’s so snappy I love it

@SpookDog

Hi mate yes I’ve done it on this bike I’ve got now, it’s a dtre engine in a Dtr frame, it’s really simple. @Calum did a post about it and what you need! Here you go

https://dt125r.co.uk/topic/13/kick-start-conversion-dtre

For the sake of splitting engine I’d just split it and redo the cases with Threebond 1215, then won’t have any future problems, only takes an hour max to split cases

@SpookDog

With my bearing I put the headstock in the freezer to shrink it ever so slightly then heat the bearing up really bit to expand it, then quickly drop it on few taps with a rod on the inner race of the bearing all the way around and it seated lovely.
First one I’ve done on dtr though I did one on a kx and the tolerances was so tight it didn’t work I had to get a tube that fit over the stem and onto the inner race and long enough to clear the top and few taps with hammer got it seated, wouldn’t damage the bearing as all force was on the inner race

@SpookDog
I wouldn’t go with POR-15 for the tank sealer, it’s only a single part product and doesn’t hold that long even with the best prep.
I went with Caswell it’s a USA brand but they stock it here in the UK. It’s 2 part epoxy resin and good for all ethanol so will work with the E10 if you need to put it in.

It also seals pin holes in the tank very well,
I filled my tank with pure white vinegar from the shops that I got for 25p to the brim and left it for 2 days, give it a shake every now and then.
After that rinse with hose pipe to clean out then let dry. Get some 99% pure acetone or best you can get and poor that in around 5L and give it a good shake then drain and leave in sun to dry. Then you are ready for mixing up and pouring in, got to be bone dry before you add the stuff. I’ve got some pictures of my tank I’ll add

@HOTSHOT-III

Lovely wheels you’ve got listed!
I could spend all the house savings on the bits you’ve got listed but the mrs wouldn’t be happy
Glad you’re out and about and recovered now and still staying on the forum and around DTs!
I’ll have to come show you my DT when I’ve finished it but slow process at the moment as I’ve just picked up a RM125 for some offroad fun for the time being.

Only problem with these bikes as they like to go through pistons as being 40bhp 125 but I’ve invested in dial bore gauge, micrometer and proper honing tools for the barrel so I can a very accurate measurement.

I use Castrol power 1 race, fully synthetic can get it from halfords.

I always get mine up to temp for a few miles then always at 10k rpm most of the time in each gears, always gets a beating when it comes out and never had an issue with anything sticking

@HOTSHOT-III

Thank you for explaining mate I’ll give it a go now

I found the 3NC-00 cdi on my 96 French import wicked! revved to the moon and went off the clocks no problem on stock gearing

What I do mate is, start it up with no coolant slowly add coolant this for me helps stock air bubbles

@Vcelicka

Like @HOTSHOT-III said the best Coil pack is the OEM Yamaha one, I couldn’t get my hands on a decent one, but I did trail a few and the best one for me was off yambits, just order a NGK cap for it and screw it on, I’ve not had a single problem with it and starts and revs all the way to 11800 on my rpm and been spot on

Welcome to the group mate,

If it was running absolutely fine for couple months then something is starting to fail or carb is getting blocked,

What i would do is try a brand new plug, BR9ES if that doesn’t sort it could be your coil pack breaking up at high rpm, Also sure jets are not blocked but if it’s cutting power it is either fuel or spark, so start with a new plug first

Let us know how you get on

@SpookDog

I’ve sorted the bike now, I’ve got some videos,
Trouble with a bike that been “molested” so what I did with airbox was cut a sheet of thin metal and tiger sealed it onto the top of the cut airbox then marked out snorkel hole size cut that out and tiger sealed that on, so it’s got the correct amount of air now, and jetting wise it’s on 27.5 pilot and 210 main, (I’ll have to do some plug chops) but airscrew all the way in so putting a 30 in and that will be sorted, I’ve even took it for a ride and it goes very well no more hanging revs and can snap the throttle from idle to all the way open and no hesitation, jet seems big but that’s what it is it runs lovely.

The only reason I asked about the washer below the needle as mine didn’t come with any but I’ve bought some 0.5mm thick rivet washers that fit lovely in there I just wanted to know the original thickness of the one on the bottom so I can match it with these as without washer on the bottom it puts the needle even further down

@HOTSHOT-III

Thank you for all that info bud if doesn’t go un missed!

So today I’m going to look at my slide to see what number it has on it, just looking at the emulsion tube needle etc it’s definitely the higher jetting rather than the dtre 210, 17.5

As yesterday I tried the 20 pilot that came in the carb and had to have the airscrew right in so definitely needs upjet so I can have it 1 to 1.5 turns out so with the 17.5 the standard DTRE engine has that’ll be to low, maybe it’s because it’s got some “performance mods” on to the bike bike now I don’t know, I’ve ordered from that jets place now looks like one of the better sites and got good reviews, I’ve ordered 210 main, 220 main, and 240,

22.5 pilot, 25 pilot and 27.5 pilot just incase I need to go to 27.5 not sure why I would but always good to have incase,

I paid £8 before for them other jets that should ring alarm bells as I got like 20 jets for that price and now I’m paying £5 a jet

Ready for the road soon
I did order a horn for the bike from AliExpress and it cost me 40p with free shipping and it arrived in 8 days it works like a horn and can’t complain for 40p

@SpookDog @HOTSHOT-III

I feel like a right idiot…

So the main problem was the split in the inlet rubber got new one on. But when I was changing the jets I had a jet that came in the carb already and that 20 pilot from mikuni I put it next to a .20 pilot I had from my new jets and the new jet holes was tiny compared to this one, to get the same size holes from my new jets compared to this 20 I had would be like a 35…

Never buy jets from eBay that’s a Chinese seller I guess

So anyways my mates got a dt so I rang him up and borrowed a 25 pilot and sure thing it ran the sweetest ever!! So now I need to order a 25 pilot from a good company also will probably get a 240 main jet aswell while I’m at it

@SpookDog

Result ay mate! Was on the phone with @HOTSHOT-III and we was running through some stuff and made me think to double check and check again everything.

I’ve just picked my spare one up from my mums so will be putting that one on tomorrow.

As regards of jetting I’ve got

4th clip on needle
240 main
.25 pilot

I’m sure that’s correct for my year as it’s an DTRE engine.
I just wasn’t sure if I needed to upjet at all as I’ve got dep, Boyseen dual stage reeds and 1mm oversize re bore?

I will do a plug chop when it’s all running properly and go from there

@HOTSHOT-III

I can always change float height back to 16mm not an issue, I’ve got the snorkel hopefully coming tomorrow so I can patch the airbox up and have the correct amount of air coming in as it should be so can work from there as it’s all guess work without