DT125R FORUM

@daley1471 This stuff is ace, I ran it in my 1998 with no issues. Conforms to the Japanese industry standard for racing two-stroke oil, injector or premix (keep the oil pump) and exactly the same colour as Motorex Cross Power 2T which costs around 3 times as much:

https://www.ebay.co.uk/itm/290755921657?_skw=exol+optima+2t&epid=662909457&itmmeta=01K3KZWN7X8TD3CT7J8TBWWTQM&hash=item43b26746f9:g:Rq8AAOSwNJNmTfy6&itmprp=enc%3AAQAKAAAA8FkggFvd1GGDu0w3yXCmi1eNjL639xZVAqN3GclCxJmhzHehkechOcOu6rKbPf6X3dTEaSCllMI0FK66SVRoBi1YvRcZX%2Bae7kD%2BtGSe1upOU3uTySQplz%2FYz4xCi%2F66aN0TkIWPsOJmsPcDLUFo04Plnudr35mJxW6VDHG%2FZ3XI941jXeZ0v0uWesuVeVy2o%2FFVrIteHaIem0OqtoLl7hWwWvFfmEmgmnxUnaukWFcdZmCc3gwCD6DdI3iuXCkV7b2mc3MNC0YLn%2F8BVAk%2BRNVOhVWQGhq%2FEg1cHyYucM%2FTfJ0Qr81OWy6x3rX7lMwOHw%3D%3D|tkp%3ABFBMjtTy_5xm

You can save even more by getting a few mates together and chipping in for the 20L:

https://www.ebay.co.uk/itm/196815078744?_skw=exol+optima+2t&epid=662909457&itmmeta=01K3KZWN7XMEWDW0HTKNRTT4FB&hash=item2dd317c558:g:JCUAAOSwJUdnNzDA&itmprp=enc%3AAQAKAAAA8FkggFvd1GGDu0w3yXCmi1d5yFGR2t%2FVv642o7SZ%2By8tY8EX3mx0sT4B2NFP7NyXC1bOCaKJA3mDNs30MBBKxR6qDwyLCnLzA9CaZlsdRS9PelaNJuhVxlMpTNpRXYhg2TpeKMDUsTmdFXhFTDaLBZmzY5ejZL%2FcNwak1LazWORcorR1RMxom%2FVZaX3F9F%2B99VGjshlYStdYGxG9C9jbGED8yUQiIH1W1sB4BqeUx0A0CThyXPUxSt%2BLJm%2BpXfFVE%2FxtLsju1TgbvbKm0%2FV3tgvI5DjdBr0I3sPElNqlZrYghx%2BsU5rLe%2F4E8I2S21Ih6w%3D%3D|tkp%3ABFBMjtTy_5xm

Get a Haynes manual and read up on doing an oil pump bleed, and think about a clear oil line kit from Yambits for peace of mind.

Servicing intervals kind of depends how and where you ride but I'd start with a few air filter elements from Yambits (as good as genuine but half the price, if you get a few you can wash and re-oil them in rotation) and a cable oiler for £4.99, and order a gearbox oil drain bolt and some copper washers from Fowlers (£2 genuine). These are designed to stretch and break if overtightened, a PITA as you have to get the clutch cover off and wind out the broken part but better than needing new crankcases. Everyone overtightens these so it's one of those things worth buying genuine. Tightening torque is 15Nm so get a 1/4" drive torque wrench from a cycle shop (under £20 as so much stuff on MTBs has torque values now) and this will be good for most of the bolts around the bike like fork/axle clamps etc.

Look around for a good deal on a box of BR9ES spark plugs, and fit an NGK LB05EMH plug cap (the type moulded into one piece of rubber).

Have a really good look at the chain and sprockets and use quality replacements if in any doubt.

Get a grease gun for the rear suspension linkage bushes and there are posts on here showing you how to fit them to later bikes' swingarms/relay arms where Yamaha deleted them.

Get 5 litres of Gunk/Jizer to wash the bike, and 5 litres of WD40 with the free spray bottle from a motor factors; after washing throw old towels over the wheels to protect the tyres/brakes/spoke nipples and just WD40 the whole bike, specially around the engine/carb/shock/wiring. This protects it and makes it easier to wash next time, as well as preventing common DTR problems like seized carb mixture screws etc.

A MX bike stand (the type where you wheel the bike over it and press a pedal to raise it) makes everything a lot easier, specially chain maintenence and oil level checking.

Hope all the above doesn't put you off but a lot of bike shops these days aren't really up to speed with 90s two strokes so it can be of great value and very rewarding to get into doing all this stuff yourself.

@SpookDog Hope you're well bud?

https://www.ebay.co.uk/itm/265105508108?_skw=dt125r&itmmeta=01K3KZJVZXTDXFQSV8F8825AK9&hash=item3db985070c:g:fR0AAOSwPklgYe8r

https://www.ebay.co.uk/itm/254920918177?_skw=dt125r&itmmeta=01K3KZJVZXGQ7GA5E0N5ETX8JA&hash=item3b5a7884a1:g:27sAAOSwBTVgYbuc

@mbmO8 Good question, within reason the short answer is no.

Closing the throttle at high engine speed is one of the problems Autolube solves because the pump being driven by the crankshaft means it's still delivering enough oil to prevent seizure.

It's fairly common on competition bikes running premix for them to seize if you chop the throttle at high rpm, like at the end of a long straight at a beach race for example.

To be honest I wouldn't be adding extra oil to the fuel as this can actually cause engine damage by creating a lean running condition; a percentage of oil mixed with the fuel equates to that percentage less fuel right across the engine's load and speed range. Autolube is one of the most reliable lubrication systems ever made; if you're worried, double check your oil pump adjustment/delivery rate and get an oil pump rebuild kit from Yambits if the pump is rebuildable. And run a genuine throttle cable as those £12 pattern ones aren't great.

@gary76 This is probably a better way of doing it to be honest: https://www.aeb-developpement.com/en/910-complete-mxe-250-aeb-engine

@Michaelashbrook As others have said it doesn’t make any difference which hose goes where, and they’re not really needed in a country like the UK with mild winters. However they also serve another purpose which is to make the cooling system self-bleeding when refilling as the one on the thermostat housing comes out above the actual thermostat, so all you have to do is fill the radiator slowly and you end up with no trapped air (this is why bikes like the 350LC and a lot of MX bikes have bleed bolts on the head and barrel etc.). So it’s useful to just run a single hose from one banjo straight to the other and bypass the carb; you still retain the self-bleeding cooling system but it’s a lot easier to get the carb off for cleaning, jetting and float height changes etc.

@gary76 I think mine took about 3 weeks to arrive via DHL when I bought it directly from Borut, and I received tracking numbers etc. Just seen your other post, have you checked your spam folder for confirmation emails etc.? I forget that sometimes when ordering stuff lol

@Calum I think it's something like that yes, that part of the crankcase is just an empty space.

@mbmO8 All DTRs have this, can't remember the reason for it offhand but it's nothing to worry about.

@SpookDog My French '93 frame/engine numbers started 4BL (no JYA prefix) even though it had 3NC electrics, I think 4BL might just mean it was originally sold in France.

Re DTR or DTRe, a later DTRe will have different spigots for the fuel tank rubbers and a mount for the ignition switch on the frame just behind the headstock as they had that funny shaped top yoke with a hole for the steering lock pin to engage in. You can also tell an old shape DTRE frame from a DTR as it will have an extra mounting lug for the starter solenoid just below the battery, and I think mine also had some other mounting lugs on the very bottom of the engine cradle for a small cover to protect the starter motor.

How's your suspension linkage job going?

@Hark_Ptooie I'd be looking at the right side powervalve cap judging by your description. One of these broke once on an RD500LC I used to have (same part) on a group ride about 60 miles from home and even over the sound of four cylinders I could hear it, I honestly thought it had blown up and I was very relieved to find it was only that.

@Stevie-Wonder Saw this on Facebook, well done buddy Those Diversions are great bikes, back in the day they had a reputation for being reliable and doing everything well.

@Calum I have to think things through quite carefully to avoid the jobs piling up. For example, where I live is right on the edge of where the Purbeck sand/gravel ends and the Salisbury Plain chalk downland starts so for most of the year I head in the Purbeck general direction. It trashes drivetrains as you can imagine but makes for easier cleaning as all the mud brushes off even in winter. And having several bikes means it's essential to clean the one I've ridden before going out on one of the others.

Whereas out on the chalk it's great in summer but with even light rain you get that tacky cake mix style mud which sticks to everything meaning bikes need to actually be washed; more time-consuming and a leading cause of knackered suspension forks. RockShox seem slightly more prone to this than Fox which is rather annoying as IMO the ride quality is slightly better due to the independently adjustable positive and negative air chambers. I ended up robbing parts from four different sets of U-Turn Revelations to build one good one, some of them looked immaculate on the outside but it just depends how much they've been jet washed.

@Calum Thanks bud, I liked the look of the On One build you posted up on here a while ago. In fact after getting this Stumpjumper, to save time/cleaning I put the eXotic fork back in my hardtail and put it back to rim brakes so I had something easier to live with that I could just hop on and ride in the meantime. Seemed counter-intuitive to take on yet another project but that only took me a few days and meant I could then concentrate on the Stumpjumper build. Had a few nice road rides in the summer heatwave as well

Here are some pics of my 2007 Stumpjumper FSR Comp (large) which I've just rebuilt.

I’ve called this bike “The Time Capsule” because when I saw it advertised on eBay it was completely original right down to the tyres; even the rear had no discernible wear. Well worth a 300-mile round trip to Wales to collect it whereupon the seller informed me he bought it new 18 years ago, rode it home from the shop and it never left his garage again!

5 weeks on it’s now had a full recommission which includes:

Brand new wheelset built using new Shimano Deore XT M756 rear hub, original Specialized Stout front with new SKF 6001 2RS bearings, NukeProof Dolos rims and Sapim Race double butted spokes with coloured alloy nipples. Spoke nipple washers can't be seen in the pics but spread the load around the spoke holes in non-eyeletted rims and make truing easier.

Original Fox Float 120 fork fully serviced with Fox genuine parts and SKF green dust seals. Travel kicked out to 140mm during the service by removing the plastic spacer underneath the air piston whilst they were apart (this is literally Poor Man’s TALAS travel adjustment as some of the higher-end 2007s were supplied with the TALAS (Travel Adjustable Linear Air Spring) fork where you can adjust the travel externally on-the-fly; pretty cool when new but 18 years on these Floats are simpler and easier to service).

OEM Triad shock fully serviced likewise using Fox genuine parts, a nitrogen needle kit and RockShox shock pump to inflate the chamber behind the IFP.

Every chassis bearing has been replaced with full complement bearings; these have no cage and are packed with balls to take higher loads in low-speed applications. New headset bearings but the OEM Cane Creek cups and crown race were fine so I didn't disturb them.

Shimano Deore XT T8100 brakes; these deliver XT quality without the fiddly servo-wave levers. 180 front/160 rear rotors.

3 x 9 transmission with Shimano 73mm external BB and 2-piece crankset (these are a modern take on the old Hollowtech II cranks). Deore Shadow rear derailleur with ballraced jockey wheels as these do make a difference to shifting performance. Interestingly the Altus shifters are Shimano’s cheapest 3 x 9 offering, yet the only ones that allow me to put the dropper post lever where I can actually reach it (it’s actually a left lever but by installing it upside down on the right handlebar, the 3 x 9 Luddite (i.e me) can also enjoy the wonders of dropper seatposts).

New 2007 FSR pivot bolt kit I was lucky enough to find on eBay; the seller thoroughly cross-examined me before allowing me to pay because he’d had so many people buy the wrong kit for their bike and then argue with him and click Return This Item. 2007 isn't all that long ago so Specialized should really still supply pivot bolt kits for these, and try and help people rebuilding older bikes a little more by providing the info on their website.

NukeProof bars, Thomson Elite X4 40mm stem (gives exactly the same seat-to-bars length as my 2007 medium running a 70mm X4 stem) and No Logo external dropper post. Magnesium platform pedals, inline cable oilers and weirdly humungous RSP bar ends; for any half-decent UK MTB ride you’ll need these for the asphalt hills. Frame downtube protector made from the original front tyre as I didn’t trust the 18-year-old Kevlar bead; I once had a rock dent the downtube on a bike <6 months old riding in the Quantock Hills which is a great way to ruin one’s day and rather upsetting.

I've wanted one of these in a large for a while as I’m right between a medium and a large according to the sizing charts of the day due to my height (5’11”). My medium (last pic in green/red) has shorter wheelbase and runs narrower rims and 2.1” tyres (this is running 2.3”s) which should mean it’s more agile than this bike but the large should have the edge in stability.

First ride on this on Tuesday and it went very well so looking forward to comparing them directly!

@SpookDog Thermostat definitely worth a look as @Calum said. Also the rad could have a blockage, it's not unheard of. I've had some success on cars blocking off the ends, filling them half full of Gunk/Jizer and giving them a good shake before rinsing with a garden hose. I like doing this on the outside of radiators as well, get loads of degreaser in the fins and it's amazing how much crap you can hose out. And I'd still take a look at the fins particulalrly on the back of the rad as they're prone to being folded over by people doing plug changes etc. which can considerably reduce flow through them. It can be quite relaxing to take a thin screwdriver and straighten every single fin and this can make DTRs run a bit cooler.

Also have you taken a look at the waterpump? Being a plastic impeller moulded onto a steel shaft it's possible this could have separated meaning it's no longer making the coolant circulate. TBH I've never known this to happen on the DTR but worth checking on a high mileage bike.

@OllieDTR Has Liam got any wheels for sale? Would be a fairly local solution...

@Corswolds89DTR It sounds like someone has put a later electrical system (and possibly engine) in your bike as to my knowledge all 1989 DTRs are either 3MB or 3NC electrical platform, both of which use the 3-wire servo.

It's a fairly common mod as the later engines are mechanically identical to the '89 onwards and some of the earlier bikes have had their wiring looms butchered over the years, 3-wire servos dying etc.

The electrical platform that ran the 5-wire servo came along in around 1999, I don't know very much about these having never owned one but if your Haynes manual is the type that covers all DTRs from 1988 to 2007 this is the model/wiring diagram you need to refer to. If your manual only covers the earlier models take a look here:

https://www.ebay.co.uk/itm/394118631267?_skw=dt125r+haynes+manual&itmmeta=01JYTRX3H7E124JNTSMMTBR2C3&hash=item5bc34d0f63:g:eEwAAOSwGXxiq26m&itmprp=enc%3AAQAKAAAA0FkggFvd1GGDu0w3yXCmi1eIah29XoGpBsiWtwJAV9MgEd61gI5Ej6kO5ykBg6ydLxdXW3P8b%2BI0B5u2Q1%2FVqwTdHslAHfiDHUTVZVRd0nEwB%2B3EyEt%2Fqn4nT3bShgiNTKLI4r%2BlwHGHSpqcBqiXi0OaUIzdE4bJuiN7ZaCKMO5%2BpxH2J%2FJeZcxY0yPrgdH2ztTJWsOGRLEAhte%2Fgd6%2FUvLi5uhZhjPtnJ8JooVoKvyNAgnWzF2UBpO6SrrdRQnNiFB%2B9nJBpQ7br0gmifIETpg%3D|tkp%3ABlBMUP649Nj2ZQ

@SpookDog Hey bud, hope you're feeling better. I did wonder what had happened to you.

Good to hear you've sorted the rear suspension

Try Salisbury Wheel Builders over in Ringwood: https://salisbury-wheel-builders.ueniweb.com/ 01202 081994

@Calum Is that a DT200R 3ET swingarm? Very nice, I bought one from Japan and it weighed literally half as much as the DT125R steel version.

However the plastic mud flap that protects the rear shock wears the (basically priceless) alloy swingarm away at the rear of the linkage bearing over time so it can be helpful to install something to prevent this. A lot of people with modern Huskies, KTMs etc. JB Weld a coin to the surface of the arm as they're prone to it as well.

I considered all that mud and chain lube floating about to be quite a harsh environment in which to try and glue two pieces of metal together so on my 250EXC I used the plastic sleeve which you get inside one of those boxes of sticky labels they sell in the Post Office cut open and cable tied on. Worked very well and I reasoned when it wears out you can easily make another one, but you might want to come up with a slightly more elegant solution for a road bike lol.

@RikuRo Try some of the DTR Facebook groups, doing this to the DT125Re is quite a popular modification and some of the sellers will supply you a kit with everything you need.

@Bilbo9000 Outstanding, I never thought of doing that! Well done Sir