Cynic

Well the saga continues. The cases have now been split but it was begining to look like i was going to have some troubles. The selector mech all stripped down loverly apart from the gearchange cross shaft, that was very happy where it was thank you, once it was out it proved to be dried up grease causing it to stick. After cleaning the muck off it is fine with good splines and straight. First, and very critical issue is someone had this motor to bits on the cheap and has caused me a load of grief that would have been easily prevented. Everything has been done up FT as in Fcuking tight, as a result i have been using the battery spanner for 5 out of the 12 case screws as well as the crank and output bearing retaining plate screws, Heat and or releasing agent has done for the rest, stud extractors generally cause more hassle than they are worth unless conditions are perfect. Soft ally cases stressed by the extractor forcing its way into the offending item, i'd sooner drill em with steadily bigger bits, go steady and slowly only clamp the drill in the chuck just enough ( then if it bites it won't snap) and use A LOT of lube and they nearly always come out clean and leave the thread relatively (depending on how straight you were) untouched. So screws removed, crankcase splitter fitted made for me by OGOAB and very thankful i am too as without him mentioning the need for the splitter i would have done no more than followed the manual that makes NO MENTION of it. I did find that the cases did bind at the back where the rubber engine mount is, why have one rubberised and not the rest?? Not really a lot on the inside, could say its almost dissapointing. The crank according to the manual should tap out of the left hand case. All i can say is I hope whoever wrote that never taps me on the head or i'll be out for a month. The good news is the gearbox is in great nick, no obvious wear, forks look good and the gearbox bearings are all good, great. This initially is where i stopped to get the parts at the beginning of the week and after pricing it all up with pattern stuff from Wemoto found that i could have it all genuine for about another 25 quid, no brainer really. The no brainer in question is TYtrials and more importantly a bloke called John, sorted all the bits i need to rebuild the bottom end as well as a complete engine set of allen screws, Don't that look prretty, get what you pay for. Something else i was informed of. Apparently bearings have speed load and temperature ratings. A bearing of the right size does not a main bearing make. A lot of pattern main bearings are just bearings the right size and not necessarily the right rating and can fail very early. John also said that if you are stripping an engine do it right, strip it RIGHT down as you will be amazed at where crud and siht gets to as well as pockets of swaf from warn bearings just waiting to knacker the new stuff. Also whenever you split the cases on a DT change the output shaft bearing cos it gets hammerd by muck and rubbish and is always always worn. And the bit thats forgotten most often? The o ring on the primary side of the crank, it is vital to the seal of the crank and apparently its very often left when people do the cranks, they just change the seals. He also went into changing the bearings themselves and how, i wont go into that now i'll save it till i've done it and can comment but it envolves a heat gun. Right now i'm ready to start changing bearings with 2 nice clean crankcase stripped down to just their bearings. I deliberately havent prettied or polished them just a REAL good clean. I dont want to scrub away the fact that its getting on for 30 years old. I'm afraid i quite like the 'comfy slipper' look. Any how a few piccies to finish for now. A nice clean case. The engine's current home.

Oh no its too late now, the only question is how and if its public...............

You can normally re-pack them with soundproofing. Looks like loft insulation but isn't. Trouble is you will prob have to drill out rivets and such for what will probably be bugger all improvement.

Wifey comes in after going out with the girls, snuggles up to her husband, hello dear she say's drunkenly i'm going to make you the happiest man in the world........... He replies....... "Don't be daft woman who is gonna help you move out at this time of night............."

Sigh dribble dribble......... If only i had a bigger garage. Whats with the front muddie on the gorgeous white one??

I have been driving trucks for the best part of ten years now, everything you say is true, i recon i prevent an accident a day, you can watch things happening and you can prevent them much as you have. You will also see all the mobile phones etc and become very aware that most car drivers think their cars stop at the side of their seat when they cut the corner you need. Or pull across. Some of the ol clunkers they teach in have got a bit of wear in em so changing slow is no bad thing. I found the gearchange ex the biggest pain in the arse getting first on the slow down,not sure if you still have to use every gear but getting that old DAF into crawler when she was moving was a bast4rd. Don't forget you can bring a manover into the driving yourself. On my test we stopped at a give way that was a reasonable slope and tried my luck taking it as the hill start. Worked to, saved me having to do it as a separate part. Anyway best of luck

A place that has been very helpful to me lately is TYtrials their business is restoring DT's and TY's.

Probably next to a pile of rocking horse siht, only kidding but they are increacingly rare, any of the auction sites really. Would need the engine no to be exact with which carb you have and that will be the trouble with any that turn up you cannot be certain that its the right one. Going on your previous thread are you sure another carb will cure your ills, it would be far easier to fix the one you have i would have thought, it may even be something else like electrics or crank seals. As far as it goes carbs very rarely actually wear out. The stuff in them does like jets and needles etc and that can be fixed. Oh and Ray, note to self, add the A on the end of your bike name.

Sorry mate but as far as i'm concern'd a dodgy chain and sprocket set can be potentially lethal. Damaging your bike hurting you or worse, if it jumped or broke and locked the rear at speed. I have experienced an iffy chain snapping and i will never skimp on a chain again. Sorry i buy chain and sprocket sets or at least known components if i'm changing the gearing, fit them as one and chuck em as one. So if you are asking me bin it, and buy a proper set.

OGOAB told me about em and you lot prob know about these guys already but: WWW.TYTRIALS.CO.UK Sorry don't know how to do the clicky bit but the people on the end of the phone at TYTrials are old school bike nuts they know DT's and TY's backwards and are quite happy to yap on about your bike and what you need. Brilliant like a breath of fresh air. All genuine parts too.

Have you tried putting the other rec back on. I recon its an electrical issue with something getting hot or a bad earth/joint somewhere. Or a cdi pick up failing. I had similar on my DT and that was one of the cdi wires had touched on the hot exhaust just enough for a very slight connection, exhaust cold engine runs, hotter it got the worse it ran till it cut out. Kicked myself when i found it.

Is the photographer being artistic? or hiding the fact its missing the LH pipe? Either way looks a treat, but i'm with drewpy on the wheels.

Tell your friend to take a long run off a short pier, you wont notice the loss of performance from some worn rings, take her out and give her (posh army voice) a damn good thrashing, like 10-15 mile blast on a motorway or such to really clear out the pipes. Take a look at my topic "Dt175 engine rebuild" and you will see just how knackerd the pistons can get and still run ok. Honestly with decent oil and run properly you can expect 20thou before any real work. Save for decoke's. And if you give it a proper blast from time to time you can avoid them too.

First and most obvious question, why?

Having used a bike running pre-mix i would go for sorting it properly, with the autolube you have the right mix all the time and you don't have to carry a bottle of the stuff everywhere you go. Its a pain in the arse to measure so you can't part fill and worst of all if the bike stands for any length they separate out. No, premix is for crossers and race bikes that you fill from a jerry can in a field. On the road its inconvenient at best. Fix it right fix it once. Ive heard it often enough growing up i'm now old enough to admit its good advice.

Ok bit further on, the top end is fubar unfortunately or unsurprisingly. This is the nasty bit on the barrel, some teenage bodging i'm not very proud of but is not all that uncommon for any old trailee, steel studs in an ally barrel they sieze and they snap. Leading to this ahem. As its on 1.25 as is and a knackerd 1.25 at that i really don't think it is worth the expence of sorting it properly. The head gasket has also failed as you can see from the pictures it was blowing at the exhaust and leaking at the head so its not surprising the piston has melted at its crown, it is also out of spec in all ways with scoring on the front and a scar from a heat sieze couple of years back. on the plus side the clutch has stripped down fine, all the plain plates are flat and the friction plates are all well in spec, the drum its self is also in great condition, in fact the only bit of wear i can see is the polishing on the clutch output shaft but thats to be expected as its a bearing surface for the basket. Thats about it for now well till i get the cases split. If you want to know or see about something specific or you have any pearls of wisdom/experience pile in. I'm not doing this as a manual, just showing that its no black art.

I'm inclined to do them, they seem OK but i have flooded the crankcases with water myself twice, so i think i would be a bit of a prat if i didn't take the oppotunity. The crank appears to be absoloutly fine i will check when its out. I have been trying ot get a photo that shows it but one of the crank seals ( LHS) was put in on the piss by whoever had it apart last. Surprised its lasted this long.

Hi mate, if you have nothing fancy on there its a good start, second the lamps are lighting, even if it is fast means that the likely hood of the fault being within the loom is unlikely. The fact that one side works fine means that the actual relay and associated guff is fine. I would be looking at the bulbs, i cannot count the amout of times i've heard "but the bulbs looked fine" after a lighting fault is found to be the bulb. Swap the bulbs from side to side that will cost nothing but time and see what happens, i would not be surprised if the problem swaps over. Failing that then i would be looking inside the lampholders at the connections.

Hi all, my DT engine is a bit sick. She has finally called time and demanded some serious attention. She had an overhaul of the running gear about 10 years ago but the motor was ok and as one of the ain't broke brigade, i left well alone.... Point is i've established that the crank seals have gone so am pulling the motor down, i've started from the off taking pictures so i am going to try and do it as a long thread and try and scare away some of the fantasies over whats inside these motors and that its relatively simple to tackle the big jobs. Anyho this is the most recent piccy of the old girl just b4 i set to getting the motor out.. The first thing to do is tidy the garage, yes seriously, the second is go to the pound shop. I got 20 odd assorted plastic containers with lids, 10 round foil tins and a stainless turkey baster (perfect for degreasing) with a bottle of lamp oil ( like parafin but a third of the price) for under a tenner. Then sort out your bench, and your storage for the stripped parts Now, still not very exciting and rather tedious, clean all the grease oil and rubbish off the outside. Otherwise you will get it over you tools, yourself, the bench and most importantly the nice clean internals. This is where i'm upto at the mo. I will be pulling the barrel and the clutch etc this week and looking into getting the bits orderd to fix it, the awqward one being a barrel, anyway i'll finish on a shot of the motor as it is at the minute and i'll update later in the week. One nice clean motor.....

Thats propb what will happen, need to find a good front muddie tho..... You are missing the point, it cost me 20 quid TWENTY YEARS ago, we have both been through quite a lot since. It survived me as a teen, my old mans mid life crisis ( got pulled after pulling a wheelie long enough to take him to fourth gear up gold street in northampton, when he took off his lid the copper told him to fcuk off and grow up LOL.) i used it for a few years with the TRF green laning and even commuted to market harborough on it for 6 weeks one winter , thats a 40 odd mile run each way. Its been in general on and off use ever since. It is personal and i dont want to steralise it by replacing half of it. HA as for original ha ha ha its got the front end from a DTR125, noblies and me and mother nature, with a little help from the black stuff have removed all the non essential parts. I say again, a lot of resto's that i see have so few of the original components left in em that they should be on a bloody Q plate but they win prizes, surely that is missing the point.

But its never had a 'former glory' the bloke who bought it new used it for enduro and i got it as a worn out non runner at 6 years old (the bike that is)for twenty quid twenty odd years ago. I ask the same question as i said to pete, WHY is it better to take away what it is, a lot of resto's read like a shopping list of NOS parts.

Sorry mate the powervalve isnt a magic button, youve been told its been profesionally tuned but no-one fitted the powervalve electrics, sorry but someone is jerking your chain. If all you do is set the valve low, the power will go low and all the carberation goes to ratshit and it wont rev out. It will wheelie everywhere (for about 10min). They are either restricted or not you can't really turn them up and down like a light. The only thing to do is fit a std pipe, std jets and lock the valve back where it should be, or leave well alone and be a bit naughty.

Having a chat at work today and Pete asked me when i was going to restore the old nail (the DT). I said i wouldnt want to as after having the bike since 1988 just about every scratch dent and bodge are mine. Its generally tidy although the engine needs some hugs and kisses, rattle can paintjob and it has been used to commute, trail, enduro. Everything. He couldn't see this and said it would look great if i restored it to its former glory. We couldnt agree and i wonderd what you lot thought......?

Does it make a buzzing noise when you turn on the ig? If you have the full fat 33bhp jobbie (with noise)you may have landed on a full power version that was never restricted or de restricted by yamaha, as to restricting it its Not quite that simple. you will need to re-restrict it properly, as in remove the powervalve computer and i believe swap the cdi, peg the valve in the restricted position, correct the carburation change the carb top and restrict the exhaust effectively. If you have the garage quicky method i would just ride it cos what you think is 30 odd hp will really be about 18 but it comes as a big slap at about 7000rpm. Did no end of these as an oily youth in denim, the TZR was the big thing in my day (88) and i could wind em up pretty good in the end, could never afford one m'self.

This is meant to reasure NOT scare..... Under my bench at the moment i have a 125MX engine that would start first kick and give useable performance yet when i took the barrel off the rings FELL out and i could measure the piston skirt clearance well over 1 mm although it is on its std bore. The engines in the DT's from the late seventies to the watercooled stuff are built to last, they will run and run, even when they are half dead they will give their all. With a recent bore and bearings (done properly) that engine will be great for another 20 thou.