satelliteone

Some of the rebuild pix ---------------------------------------------------------------------------------------------------------------------------------------- Well peeps, not been around on here for a while, but i have finished my TZR, this week and fresh MOT end of the month. here is my web site for the specs etc... http://tzr125r.pen.io/ but just to show you how this bike has turned out. It runs flawless, and goes like stink.sounds great, .It rides good as it looks! Roll on my next project. 2012

hi guys, i owned a dtr 125 r 2003 model and de-restricted it. 90mph and full power all the way up the power band. The speedo has a reed switch, pull it out, away from the clock face, tape it up and leave. exhaust, either go down the full DEP route, but i didnt like the dep. too toppy for me, 8K power band..mmmm Use the original, but cut the restrictor out of the flange, like in the first post, and then cut along the seam in the expansion chamber, open up the zorst, knock the two bits of metal "wind breakers" out. TIG reweld the two halves back, in perfect postion again.The original zorst produces better power IMO. some of the newer RE`s and X DTR`s have a carbon CAT in the front of the pipe. this needs to be taken out too, or just buy an older zorst. carbs..mmmm.. standard is 28mm flat side or even older 90`s is a 26mm mikuni`s , just make sure the jetting is perfect. if you can, find a TZR125R Dellorto 32mm with the inlet rubber + reed block that will make a huge difference. The TZR125R 4DL model has the shares the same engine, just the CDI and the carb + exhaust makes 33HP the standard cylinder head is designed for lower compresson, change it also. to say a 4FU, the compression will come up. http://www.ebay.co.uk/itm/Yamaha-TZR125-93-97-DT125-TDR125-Cylinder-Head-13815-/280716578375?pt=UK_Motorcycle_Parts&hash=item415c030e47 hope it helps..

which model is it?.. 2RK?

choaw dude, am getting it sorted. got the fairing trial fitted, with rad scoop today decals fitted also.

Bought this awesome peice of kit for a grand sum of 250 quid. In a bad running state, but the condition is prety good. Only done 17.4KM in pounds and pence a smidge over 10K miles. 34HP, Brembo wheels/brakes delorto 32mm carb italian import. UK road reg`ed. box of spares too.. plus the most of the fairing, big big smile!.. going to take a wee while to get back on the road. fitted the bits toghter just to see what the bike looks like.. on with the restore! engine is now out, needs a new crank bearing.. slight play.. the fork seals are knackered..too new bar ends and grips, and a bloody goo clean up.. forks back on with new seals. along with a new tyre looking not too bad... so far.. needing a starter motor, and screen.. small list of parts iam trawling the net for.. also i seen these.. 400 quid!.. i like alot.. ongoing..still...

i got a feeling, the squish band on the 3bn head is trapping compression, u think that my head has 1mm taken off. the piston is quite close to the douhgnut area. gases are pretty squished in the recess. probs explain why gaskets go pop quit a bit. lookin out for a 3mb head now. i need 13:1 compression... also been looking into better head gasket design, bout to talk to these guys. custom made! http://www.ferriday.co.uk/copper/copper.shtml

mmm sounds like the bloody plug to me trying to break down. and i suppose the coil could do the same if say was slightly faulty.. Another thing thats well over looked is the pickup from the flywheel, dead easy to get at, just need to take the flywheel cover off, have a look at it, to see if any rust has formed on the head of the pickup, or even small metal fillings. Give it a good clean. other than that it is starving of fuel. that could be many reasons. Float level, flow, jets/needle position..bla bla bla..

wow, a rarer red one, not often u see many that colour now adays. Yup you will have fun with seized bolts n stuff, its an art to get them out for sure, if u can, give them a alot of heat too if ya can, the stuff i use is a PLUSGAS, its a spray we use at work. Hit it with the blow torch too.. other than that is drilling the little buggers out, tap n die set and some new fresh bolts pref stainless.. good luck, its all fun, u`ll work through it.. great lookin bike chap..

yup normal water is fine, u would need an antifreeze in the winter.Never heard such horrlicks! with adding stuff to water for this or that or other. come on use your sense. not only that, u instantly told me earlier that i was wrong about an exhaust!.. common chap.. pls make 100% certain ur right before flaming. make u look like a right pratt. DTr are terrible for holding head gaskets. Useless design IMO. the gen yam gaskets seem to work better, but why ohh why did`nt yam use O ring technology.. or better gasket design..the head is so small no wonder its warps. and gettin a torque wrench on the head!.. whilst in the frame.. im thinking of changing the design my self. plain copper gaskets. laser cut!

hey ya old git, justa question really, what year was your pipe?.. u may or not know the later pipes had 2 half moon shaped metal peices in side. this was to slow the gas`s in the expansion chamber. Also a restriction tube in the front. Which u cut out and open up the size of the neck. The older pipes say for the 95-98 models.. did`nt have this in them, just the neck restriction. The really new pipes say the RE models have a catalytic converter in them. pls take ur time reading this. http://dtr125.net/tuningnewer.htm The DEP and many other pipes, powerband comes in around the 7.5K revs. full chat 8-10K. Ideal when ya need full power on a small track. Crap for road use. The orignal yam pipe, was sec made for the DTR, tuned. When deres`s, the power band kicks in at 6K. Ends about 10K. When ur using the bike on roads, ur still pulling in 6th gear at 6.5K unlike a DEP, which power would come off, and u would change down to 5th. So the original pipe pulls harder and stronger.

oooooo.. just found this thread..My DTR compression is high, the lip near the squish area.. on the 3BN has ben taken off..But i have encountered a problem.. it keeps blowing head gaskets. I wonder the 3MB version would help. Yam have said there are diffent head gaskets! The TZR RR model has a higher compression, i would love to know what head it uses. I got a feeling the 3BN design was for the lower compression DTR engines. Also the TZR RR uses the 32mm carb. unlike the 26mm mikuni.. any way brill thread guys!.. love it.. PS.. my new cookoo clock! well DTR bottom end, ive built.. PS2.. got some interestin info for ya guys regarding over sized pistons and PV`s.. not good!..lol

8K!!! u lucky git! on a H plate..thats awsome!.. all elbow grease rally.gunk every thing!.. power wash every thing. new oil, clean carb, free brakes!.service all the cables. grease gun the swing arm linkage, check bearings for play.. Spend a bit on tyres . chain..pads.. give one hell of a service!. U will have a great bike!.

not another 1, 210 is right on a stock motor, right compression! the 26 mikuni is a really great flat side carb. Only way to increase power is increasing the compression. better port timming, and a better zorst. The best guy to do any 2T work here in the UK is Stan stevens. google him.. TIP ..Have a look at the TZR RR spec..same engine as the DTR, u will notice some nice differnces! bigger carb!.. bigger compression. stage 3 barrel timmings!. And if u find a TZR RR model..give it to me..lol!...

thats two peeps l8tly with he same problem..why did ya pin the pv open?..curious 9k!..mmmmm..did u do a top end rebuild, checked compression std is 110PSI on a new engine! , check spark plug gap, changed the plug even!..mines revs to 11k and the power band comes in at 6K... The zorst decoked?.. all boost bottles on. air filter cleaned.. gearbox oil at the right level.. right oil in there too, not like 20W50 engine oil.. grrr.. does it drink fuel? badly. tip for ya.. DTR`s eat plugs! dont ask, i dont know why, still working that 1 out! got a feeling its the shit coils! I use NGK BR9ES, only got to look at it, and it fails!..lol so many questions!

hi ya chap. i have owned 2 KMX125 and a KDX, great bikes, but bloody exspensive for the engine, esp on the barrel replating. 90 quid a time to replate. The DTR costs me 20 quid! for a rebore!. go figure..lol, Never had problems with the front brakes, i must of been just lucky..lol Now,I currenty have this.. Done 8K miles in less than a year, 1 top end rebuild! so far, and it goes off the clock at 80mph. Has the gutted original zorst, not the DEP. more power! Vee rubber tyres, renthal bars. I love this thing!. its the nuts! DTR deff. Ohh and it does 55MPG. or in other words 105 miles before it hits reserve. the tank is 2.2 gallons, 1.8 gallon with out res,..about 130 miles on a tank!. Off road, its great, feels tight, and jumps well n balenced, I have changed the bars and stifferned up the rear too tho..orginal DTRs setups are a little too soft for me..The mono shock has a little bit more tension now. on road with the right tyres. almost knee down, takes a fair bit of doing as the bike is quite tall. power out of a corners, banked feels great!. never had a tank slapper yet..lol... differnt story in the wet tho..lol..heheh..I use vee rubber VRM056 rear, lasts about 3K mainly road use. Bridgestones are really good too. more suited to road tho.. The forks are very capable.. the frame forgiving, down falls, the original rims get rusty quick, cheapo! chineeese rims i expect. The paint on the frame seems to flake a liitle here n there, nothin to sort really...... umm... thats it really for me! DTR all the way for me, cheap to fix, cheap to run, and a very good quality 2T...good luck on your choice. ps.. the DTR forum is a great place to live as well!.. chooaaawwww

hi mad.. u sure u see the same page as me..lol.. its says Piston Kit Yamaha 2.50 TZR,DT125R,TDR,TZR250(58.90mm) tzr125 DT125r tdr125 and the 2 cylinder TZR250 (uses the same pistons). the pic is just a pic they have, not the correct for the item. http://www.pjme.co.uk/acatalog/copy_of_Yamaha_Engine_Parts_Top_End_.html if ya notice its a 58.9mm thats 2.9mm over sized than standard 56mm DTR piston. scary! for the PV. so in theory, that 1.45mm closer to the PV. i have seen crossed cables on the older dtr`s..mine is a 2003 model and it came like that from new. even in the manual it shows them straight. any way.. my new piston turned up.. old PV! 20 thou clearence 0.5mm. new modded pv.. now 40 thou.. about 1mm hate to think what a 58.9mm oversized piston would look like with a standard PV..lol PS. offset is spot on!

I see what you are saying, off center. perhaps, but the guy that done it,has been doing it 40 years, i can check too, as the cylinder sleave has a width, i can check with the calipers offset. as to 80mph..lol.. 10500 rpm is 90 on current gearing. and ive hit 11000 a few times. my chainsaw see`s that all day long.! "38.000 miles on standard and 1st oversize, and no I dont try to do 80 for twenty minute stretches" Grandad! hahah nice to know tho, i dont do 80 all the time.. it was just that saturday night.. i was thrashing the bollox off it.but then again..i always can just flick the clutch in an a emergency..which i did at supersonic speed on a B road. anyway would be nice to know that i can! If it was realiable then it would`nt of done that. and the last piston in the bike lasted 20K and Yam says to rebuild the top end every 10K miles. 2.5mm is the largest piston ive seen FOR the dtr.. scary piston here on ebay! look>> http://cgi.ebay.co.uk/Piston-Kit-Yamaha-2-50-TZR-DT125R-TDR-TZR250-58-90mm_W0QQitemZ150420615638QQcmdZViewItemQQptZUK_Motorcycle_Parts?hash=item2305c471d6 well my final thoughts.The design of the standard engine is ok. basically when it wears out..buy a new one. we all know we will repair the one we got. and to resleave the barrel to standard size is not cost effective at 180 quid! PS. that included the piston/rings/gaskets. not only that, design flaw in the bottom end too. the left hand(magneto) crank bearing wears faster than the right.why? i know. not enuf thought. Yam got it wrong!, no tollerence in effective rebores. simple. why the PV valve rotates backwards? if it rotated forwards, i would`nt be here now.

yup 2 wheels almost right, mad.vez ur spot on.. keen eye i see..lol.. to clear a few things up. the PV as fully operational, has been for the last 3K miles with this set up. the bike will go off the clock. It was rebored last year. new piston/rings. was orginally 56.00mm then after 20K miles on the original piston, rebored to the current 56.5mm. and done in a bike shop. this one is a 2003 model and the cables are not crossed. deresticted front pipe and Dep end can. Ive run the bike hard before, but saturday night, it was the amount of time it was running at 9-10K in 5th n 6th gear. about 15-20 miles at night. racing a car. at 80mph plus. The bikes powerband was up all the time. till i was gettin to the end of the run and backed off the throttle, and within 30 secs.. power just went, barly running.blown. When stripped, piston ring fragments were shaken out of the exhaust. the PV valve had horizontal dents. like where the edge of the rings were bedding into the alloy. No damage to the exhaust port., the bore only had 2 small light lines above the exhaust port. u can clearly see impact damage on the PV. its deff PV valve that caused the ring strikes. got to be the heat and exspansion of the piston and the closeness of the rings to the PV. and as mad said, when the piston was comming up and the PV rolling back/shutting down the port, that caused it. Dremmel time me thinks on the PV!..lol imagine if it was say 2.5mm over sized!. probally within limits on a standard bore.

hi all, blew my DTR up this week end, what i have found, seems like the power valve made contact with the piston rings, the power valve is soo vey close to the rings, and the barrel was rebored 0.5mm over sized. its done a good few k miles before it went pop.. but i was 80+ for 15-ish miles 10k revs. backed off the throttle ,and pop. was thrashng the bollox off of it. over sizing the bore makes the rings closer to the P.V. so my question is, would the massive heat in the piston at full chat. expand so far, that contact with the power valve caused this. also, pic of the PV in the shut position , closesst to a piston ring. why the dtr shuts the port down by roating the P.V backwards (clockwise) is beond me.

thought i`d reply, i got pulled on boxing day, was riding though deserted streets, in my town, on the way to my dads. I get pulled by the plod. The plod sad my plate is too small. i said it was MOT`ed like that and on the bike when i bought it. he just said get it changed, I havent yet, plus i have passed loads of traffic plods also since. But any way, iam just about to get a legal sail(plate) to just please mr plod.. PS.. ive done 4K miles on this plate. 12 months..with out gettin pulled..

my DT on gps will just do 85 flat out with the wind behind me. 70mph all day long. 17T front standard rear sproket. No DEP un restricted exhaust.DPp rear pipe only to add here is that ive never seen a dt do over 100mph, its got problems with the wind factor and torque. now a TZR RR model thats a differnt story! 110mph flat out!. same engine, better compression and a tuned barrel and head tied to a different ratios in the g box. but hey, DT`s rock. would love a WR125! and do some mods!