DT125R FORUM

@SpookDog said in Washer in fork position?:

Can anyone please tell me where the washer is supposed to be in the fork leg? Under the seals or between them?
The manual isn’t helpful as some bikes have 2 and some 1. Mine only has room for 1 but I don’t know where it goes

I never had any fitted to the forks I have, but there is a gap for them…

Mine come out below the oil seal, so in order bottom up it was guide bush then washer then oil seal then cir clip then dust seal. Certain models have one installed either side of the oil seal but mine just had below installed, hope this helps

@SpookDog Haha no worries mate. Had me looking everywhere for 41.00mm . Yeah i found another post on here and the guy had ordered them ones off brooks and said they worked perfectly so i ordered them up earlier. Ordered some paints too so should have some pretty fresh forks by the end if all goes well. Going to strip the paint off them tomorrow and address any pitting on the stancions etc

@SpookDog Yeah i may have to do that if it comes to it then. Hitting dead ends everywhere trying to find a set of bushes though. Cant find anywhere with the measurments you privided. I have phoned around and everywhere to main dealers and suspension specialists and all im getting is that the parts for these forks have been discontinued. May have to just look into doing a fork conversion if i cant find any or just hope that the bushes i have that come out them initially arent as mashed as they look . Not ideal but i cant see any other options

@SpookDog Ace mate cheers for that! Will get them ordered up . Yeah it did finally crack after a hell of allot of heat and effort . I'll get the dremel on it and open up the base of the leg a tad so the tolerance isn't so close between the bolt and fork perhaps. One crush washer is ceased solid in there so hopefully that'll allow me to get that out a bit easier too to replace. I'll no doubt strip them again next winter and get them powder coated as they are in a bit of a state but the aim is just to have a bit of fun this summer while i get my other bike sorted. Also the damper rods in my forks dont have the 27mm hex or infact any kind of way of undoing them from the inside its just smooth so i'll be getting a refund on that £24 tool i bought the other day haha thankfully the broom handle saved the day . Slight pitting high up on the stancion not really in reach of the seals unless i go flying off an mx jump to flat but any ideas with whats best for sorting them out a bit? From what ive seen online people use a bit of 1500 grit to take the high points off and maybe even using some kind of expoxy resin to fill the pits if needed. May look into that a bit more in the meantime too. Thanks again mate for the help, much appreciated

Managed to strip down both fork legs and cleaned them all up. Few replacement parts i need to get hold of. Main thing being all 4 bushes, cant seem to find them anywhere but can find somewhere that sells various sizes just not under the name of the bike so if anybody knows the size or where i can find the sizes for the bushes needed for a 2005 DT125x id be massively appreciative.
Will also be replacing the clip above the oil seal, the O ring around the top nut and the allen bolts at the bottom with the crush washers and of course the oil and dust seals. Already found most of that but just need to know where to get the bushes from or at least know where i can find the dimensions for them. Cheers people

@SpookDog The one leg stripped nice and easily. I left the one i suspected to be a nightmare last and it is. Head of the allen bolt ceased in the bottom of the fork leg. Tonnes of heat and a meter long breaker bar with my fat self bouncing off the end of it still wont crack it free . Impact gun wont free it either. May run it to a car garage local and get one of their windy guns on it. By the state of the first stripped leg i will be replacing bushes too. Brooks suspension you mentioned a few posts ago i looked at but i cant seem to see them stocking the ones i need + all i can find is pyramid ones being sold everywhere which i remember someone mentioning was crap?. Any ideas where else to try? Also there was no 27mm hex on the top of the damper rod it was just smooth . Tapped a broom stick into it though and worked fine thankfully, wish the same could be said for the other

@SpookDog said in Fork seal replacement:

If you’re replacing the seals you may as well replace the bushes at the same time (Brooks suspension sells top & bottom bushes)…
You can use an old broom handle to tap into the 27mm female fitting inside the fork and turn/hold it with pipe grips…
Any seize/sticking is usually the 10mm Allen bolt head being corroded to the ally fork bottom (not the threads) White crusty crap builds up between the two different metals. I use silicon sealant to fill & seal the gap between the two, or at least cover and waterproof the bottom of the forks…

I’ve had to drill out the Allen bolts from both sets of forks I’ve worked on. I drilled them out to 10.5 - 11mm then hammered the Allen key into them and got good purchase. Loads of heat was needed! Even after I’d undone and removed the inner (with a 27mm tool-bit I bought for £22) and it was just the bolt head stuck in the fork bottom!!…

Oh god i hope i dont have the same issue with that allen bolt at the bottom of the fork but i do have a feeling i will as i had a go a while a ago and cracking one free and it didnt budge just thought i was going to round it off so i stopped. I have bought the 27mm for the inside and i do have an impact gun now which may help free up that bolt at the bottom. I will definitely apply a load of heat like you mentioned and ive soaked it in a tonne of penetrative fluid also. Aim is to give it a go tomorrow so wish me luck haha. I was hoping that the bushes will be ok to be reused as there's no play that i can feel in it. Just oil and dust seals and some fresh oil and i do have a tub of copper crush washers that im sure will have the right size in for the bottom of the fork. Worst case i will have to drill the allen keys out, any ideas where i could pick up a couple new ones of them from if so?

@HOTSHOT-III Absolute perfect response mate was just what i was hoping for haha thanks mate. I dont have a spare spindle unfortunately but i could definitely knock something up to do the job perfectly just needed those sizes you've provided. Cheers for that

@HOTSHOT-III said in Fork seal replacement:

If the forks are the same as the early bikes you need a 10mm allen key/hex bit for the allen bolt at the bottom of the slider, and a 27mm hex bit to hold the damper rod which will allow you to undo the bolt:

https://www.uktools.com/27mm-12drive-hex-impact-socket.html

The damper rod is actually the same size hex as the rear wheel spindle (but 12-sided) so if you have an old spindle with the 27mm head in good condition but with knackered threads you can cut off the threaded part, then grind an 18mm hex onto the shank so it fits into an 18mm six-sided deep impact socket. Then just loads of 1/2" drive extension bars down the stanchion and a breaker bar on the end.

You might need an impact wrench to get them undone, IIRC I buzz gunned mine off the last time I did a set.

Hi all,
Just about to give my forks a bit of a refresh as one of them are leaking. I want to make sure i have everything set and ready for the job and i have a feeling im going to have a bit of a nightmare with the bolts on the bottom of the forks to release the damper rods. Does anyone know of the tool i can use to release the damper rod from the inside of the fork tube if the allen key at the bottom rounds off or something? Or even just the size of the hex that needs undoing so i can manufacture something for the job? Thanks in advance

2005 Yamaha Dt 125

@Calum You absolute legend! Why did i not think to look on fowlers . Thankyou so much!!, been pulling my hair out all day trying to find them somewhere to no avail. Cheers

@SpookDog link text
Not a clue if thats worked haha hopefully . Threads are 15mm long. 6mm diameter. Ive looked everywhere, contacted ebay sellers and parts distributors with no luck on this size and style. Rather frustrating as ive sprayed up loads of parts and done the rebuild and everything now and just caught up on this as i didn't realised how wrecked they was until i went to fit them. At a complete standstill now cant find them everywhere . Super eager to get it back on the road too. Typical ‍️

@SpookDog Thread size looks to be M6. Id 2mm maybe 1.5mm. I would post a pic but i dont have a clue how to on here from my phone ‍️. It just comes up with [link url] when i pretty the attach option.
Its the 2 banjo bolts, one goes into the thermostat housing on the side and the other goes directly into the head the opposite side from the thermostat.

Re: Few random questions about the rebuild
Does anyone know where i can get replacement banjo bolts for the two coolant elbows on the cylinder head?

@SpookDog yeah thats what i was planning on doing to be honest running it nice and gentle at least for the first 500 miles or so and just gradually increase it. I cant imagine the change of reeds doing a noticeable difference with the mixtures so i'll just as you say keep an eye on the plug after a couple rides or so and take it from there. Looking forward to finally getting it back on road! . Its been left in the corner of the garage as i got another bike

@SpookDog
Ace well based on what you've said ive returned that gasket set i bought and ive gone for the full Athena set instead . No point penny pinching when ive thrown over 200 at it already so i appreciate the advice. Also i did think about the syringe trick with the oil feed so i'll for sure be doing that too.
And no worries about the reed question. It does say in the boyesen instalation manual that it does tend to make the bike run slightly leaner and to tell if this is the case to do the plug test. Fresh plug, start the bike and go wide open with the throttle then shut it off and check the plug. Dont really fancy doing this with a fresh top end on first start up so yeah god knows what to do. Cross my fingers i suppose would be a good start

Hi all, currently doing the top end on my DT and have a few questions as follow.

1. Ive purchased a gasket set and its turned up slightly different as it was pictured on the ad with there being no thin orange sealant bead on the base gasket surrounding the barrel and coolant passage. Does this matter that its not there or should i purchase another gasket set? Also should i install dry or is it best to put a very fine coating of grease or 2t on it to help seat?
   And the head gasket is slightly warped from packaging, does this matter too? This is also dry and just painted black

2. Purchased dual stage Boyesen reeds, is there a chance this will mess up the mixture and i'll have to adjust the carb at all?

3. The clear oil feed from the oil pump to just behind the reed block has ended up being emptied of oil. Is there any way to bleed this prior to first start to prevent a short time of oil starvation. I'll be using plenty of oil in the bore on reasembly anyway so shouldn't be too much of an issue. From what ive read people just hold the oil pump pully wide open as soon as the bike is started to try and shorten that time. Is this right and is it all good to do this?

Most likely just over thinking things but i like to get things right first time if you know what i mean considering its my first rebuild haha thanks in advance. Been taking my time with this spraying allsorts up so it looks as fresh as possible. I'll sort some pics out to upload once its complete

@Calum Ok cheers i was thinking that. What psi will i be looking for when doing this compression test?

This issue I found to be a break in the wire that you ground from the cdi when derestricting the bike. went completely back to normal once I reterminated the connection.

sorry for the late update on this, better late than never though haha could help someone in the future with a similar issue