@gary76 That looks ace! Love the gold rims.
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HOTSHOT III
@HOTSHOT III
Posts
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Project finally finished -
DTX 125 2006 front fork damper rod holding tool@Mekoz To get the forks apart, a lot of bike shops buzz gun the bottom bolt out. It can help to get an assistant to compress the fork somehow while you do this so the spring pushes harder against the damper rod and makes it even less likely to rotate.
You would then at least have the forks apart which will make it a lot easier to examine the damper rod and see exactly what tool you need to make/buy to securely hold it when re-tightening the bottom bolt after replacing the seals etc.
Lidl impact wrench (just as good as DeWalt etc. from Screwfix) is around £60 plus battery/charger and will come in handy for removing other stuff on the bike like flywheel/primary drive gear/front sprocket nuts etc. (although I'd hesitate to use a buzz gun to re-tighten any of these).
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DTX 125 2006 front fork damper rod holding tool@Calum Thanks bud, yes I still have that tool I made somewhere. Been following this thread and it's puzzling there's no visible means of holding the damper rod like on DTR forks. Possibly someone on a WR125X forum or Facebook page might know?
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Thoughts on this billet head@YYHpilo It's a lovely piece of machining and I like the O-ring sealing but I'm not sure about omitting the thermostat. As well as regulating coolant temperature, the idea IIRC is to keep the coolant in the actual water jacket around the cylinder and head under higher pressure than the rest of the system to increase its boiling point. Even some competition bikes which don't run thermostats have restrictor plates at the outlet on top of the cylinder head to achieve this. The website says the DTR thermostat is prone to sticking; I've never had that happen on any DTR, including the one I owned for two years/30,000+ miles as a teenager. I did 3 or 4 top end rebuilds on that bike before selling it to a friend who did another few thousand miles before passing his test and getting a bigger bike, and neither of us ever touched the thermostat. I think this happens because people don't replace their coolant often enough or with the correct grade TBH. Or they just use water judging by the rust inside some of the secondhand barrels/heads I've bought in the past.
Also not sure why they'd supply stainless (not to be used in load-bearing applications) bolts for fixing the head to the cylinder; every time you take off the head (possibly to try a different squish shape according to track conditions etc. as the head is marketed as being "for tuners, not for people who don't know what they're doing") the threads in the cylinder will become a little more worn ultimately leading to failure. Incidentally the torque wrench setting for the cylinder/head studs is 13Nm whilst for the cylinder head nuts this is 22Nm (and 28Nm for the barrel nuts); the idea here is, the combination of long thread engagement, low (stud) torque value and being relatively undisturbed ensures long life for the threads in the cylinder and cases which are expensive. Surely supplying their own cylinder studs the correct length isn't beyond the wit of anyone capable of producing something as beautiful as that?
I have to say I don't go much on this guy; the upswept stainless expansion chamber appears to attach directly to the frame (which guarantees it will crack from vibration as the rubber vibration damper isn't present in the photos) and the Supermoto front caliper bracket looks a bit flimsy to me. Considering larger front disc rotor = increased braking forces, I'd want this to be at least as thick/beefy as the caliper mounting lugs on the fork slider. He's clearly good at machining and can in all probability use the two-stroke tuning equations to make an expansion chamber of the correct dimensions but beyond that, he seems to be of the rather dangerous mindset that no-one (including Yamaha) can tell him anything.
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Post derestriction jetting change on a 1998 Dtr de03@Dougster Even with a pinned powervalve the bike should pull smoothly right through the rev range, just with very little power until it comes on the pipe at 6-7000rpm.Actual backfiring could mean a CDI unit issue but this is quite rare; a lot of midrange running problems on the DTR are caused by a blocked emulsion tube in the carb.
If you've just bought the bike I'd do a full carb clean including the emulsion tube (the brass tube the main jet screws into). A lot of people (including bike shops) miss this and don't realise it comes out because you have to screw the main jet back in without the brass washer and tap it gently to remove it from the carb body. The space between this and the carb body gets blocked with moisture, dirt etc and blocks more and more holes in the tube until it just starts fourstroking and won't rev out one day as this controls the mid-throttle fuelling. Make sure the air supply to this is clear as well, it's the small brass tube on the right of the carb body just in front of the carb-to-airbox rubber. You should be able to blow through it, but only just.
You can also make future carb cleaning easier by bypassing the carb with the carb warmer hoses which come from the cooling system. These are only really needed to stop carb icing in countries with really cold winters but they serve another purpose which is to make the cooling system self-bleeding when refilling, so you don't get air gaps at the top of the cylinder head and unlike a lot of two-strokes you don't need bleed bolts in various places on the cooling system. Whilst you're getting the carb off, you can retain this feature by running a single hose directly from the banjo on the cylinder head to the one on the thermostat housing so you don't have to mess with the cooling system next time. Don't forget to check the coolant level in the radiator after doing this
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2002 Yamaha dt125r@mjmikey Koyo bearings are very good quality but did you order the correct ones for this application? I believe for crankshaft applications they need to have larger clearances to allow for heat expansion; PJME refer to this as "the correct R1 type" but I've also heard it referred to as C3/C4 clearance:
https://www.pjme.co.uk/acatalog/Yamaha-DT125LC-Crankshaft-Main-Bearing-RH-5698.html#SID=103
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Post derestriction jetting change on a 1998 Dtr de03@Dougster Most two-strokes are a bit boggy when cold and this is also when most engine damage occurs so warm it up carefully keeping the revs low for the first couple of miles.
If you mean the powervalve is pinned open, that is probably the source of your problem. Pinning the powervalve makes the DTR very difficult to ride as it robs it of low-end power without gaining any top-end.
As far as I'm aware the DE03 model ran the 5-wire servo; these are easier to find and cheaper than earlier 3-wire versions so if you don't have one on the bike ATM it might be easier than you think to sort this by having a look around eBay, Facebook DTR pages etc.
If the jets in the carb at the moment are what your manual says they should be, don't stray from this setup until you've got a servo fitted and working, it's a massive improvement to the DTR riding/ownership experience (particularly off-road) as you don't have to thrash the bike everywhere to make it do anything.
Look around eBay for a pulley/housing as well, these are the same as on most other YPVS-equipped Yamahas including the RD350YPVS, TZR/TDR250 and TZR125 (the "29L" on the inside of the pulley housing is the RD350YPVS model designation). Buy genuine powervalve cables from Fowlers (Yambits pattern ones are the wrong length) or make your own here, it's no more complicated than replacing gear cables on a mountain bike: https://dt125r.co.uk/post/28693
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New owner@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:
You can save even more by getting a few mates together and chipping in for the 20L:
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.
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Front fork spindle clamp -
Is engine braking still bad for the engine with oil injection?@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.
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Dt 230 Lanza top end@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
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Dtr 2001 hose warming pipes@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.
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Is zeeltronic still going@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
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WTF??? hole on bottom on engine@Calum I think it's something like that yes, that part of the crankcase is just an empty space.
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WTF??? hole on bottom on engine@mbmO8 All DTRs have this, can't remember the reason for it offhand but it's nothing to worry about.
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Can anyone tell me what year this frame is?@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?
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Knocking/rattling from lower right side?@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.
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Happy announcement@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. -
2007 Specialized Stumpjumper FSR Time Capsule@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.
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2007 Specialized Stumpjumper FSR Time Capsule@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
