Cynic

If you are losing the headlight when you brake your battery or the charging circuit is having problems, bad battery will play havoc with the powervalve, and you are probably right a decoke sounds like a good idea but its a spanner job. Any number of pots of crap from halfrauds wont clear the carbon from the motor.

I think he is still recovering, the truck i currently use at work had higher delivery milage that that DT. Ps OG, black is the only colour that a TDR should wear.

Hmmm, there are 2 schools of thought on this. Personally if the crank seals have had it then there are plenty of others that will be past their best, also the main and output bearings are probably worn too. So i would strip her down and do the lot. The other view is pull the duff seal out and stick in a new one in situ, i havent done this but i know bob-c has. Before we dash down that particular road try a couple of things. Take off the left side engine cover and get the motor running as best you can, now spray LOADs of wd40 or similar at the back of the generator so it covers the seal. Does it improve things. Secondly pop the gearbox breather into a glass of liquid, parafin, white spirit or similar with the engine running again see if there are any bubbles, or conversely the fluid level appearing to drop. Those 2 can give a reasonable indication of crank seal health. While you have the WD out blast all the possible leak areas on the motor, the reed cage is a favorite as well as the carb rubbers as they can perish. Again with the motor running and see if there is any improvement.

You are probably going to think i'm being really boring here but if it is in 'brilliant condition' and all standard doing 45mph reeds are about all i'd want to change. There is beleive it or not a growing group of people that ride these things to shows all over the country. If you keep it real nice and un messed with for 12 months you will get your money back real easy.

Right, first off there are better people on here for these but i'll give you my 2 peneth. The ig system is non adjustable and opperates BOTH cylinders with a wasted spark. So the coil and such are really proving themselves by the right cyl being ok. With the balance pipe the bike can (although badly) run on one carb, i'm not ruling a carb issue out but the fact that you get the backfire suggests there is fuel. Exhaust, neither here or there so long as it is clear. What happens if you swap the leads over i feel the problem may swap too, or possibly a plug. This is because to backfire the engine is igniting fuel that hasn't burnt and the only way that could really be happening is a weak or badly timed spark. I'm not ruling out other things, the doom mongers will shout crank seals which is entirely possible but to me this feels like a spark issue. Hope this helps...........

Oh you better believe it. On a dual carriageway, or really anything straight your toasted by most things once your flat out. But and its a biggy. Keep her boiling on a good and twisty A or B road and it needs a REALLY dedicated road rocket pilot to even keep up. Your laughing as they are being sterilised by the tank. You carry corner speed and have the line selection of a race bike. But of course all the 110mph DT riders will leave me standing eh.....

I think it may be flooded, like really flooded. I would say that either a jet has blocked or possibly the airfilter is wet from the washing and all the attempts to start it have chucked loads of fuel into the motor and now you have a puddle of it in the cases. Have the plug out and just give it a couple of good cranks, leave it a while, have a brew whatever then do it again. Dont put the plug in yet. Have another brew read the paper whatever. Take out the air filter and give it a check, leave it out for now. Few more cranks Now get the plug and warm it with a blow torch, kitchen stove whatever till its nice and hot NOT glowing, just enough to burn your fingers. Wack the plug in fast an hot and see if she'll go. Doesent sound very scientific but it works on chain saws. The crankcases should have vented and the hot plug helps as the heat of the plug will stop it wetting before the engine has started properly. Otherwise i can't really help. I'm ok on strokers but there is a lot of mysterious plumbing on those scoots to make it all automatic. Sorry.

Cor 60, nutter. The bit i find fasinating after actually reading this entertaining thread. My TDR is as far as it goes a DT with the ultimate bigbore. It weighs about 25kilo's more and has 4 times the power. Its pretty much the same shape and runs pretty good quality suspention and tyres designed specifically for the type of bike. Flat out? around 105 maybe 110 with the wind.

Actually for what its worth on a long dead thread, you do need a full licence to ride a 125 that has ANY performance enhansing modifications. Whatever it may be.

Got one laying in my garden, its red but looks ok as far as the foams concerned, if you want it its yours, i just havent got round to getting rid.

I'd go with cost. Its easier to make something from round section than square. Once the brit stuff was beat it didn't matter so much, then as bikes got faster the racers needed it. The DT175 got the square swinger cos the enduro lads were braking the round ones. So it came to be fitted to the road stuff because the customers wanted it. Same as now i suppose. BTW nets sweet ride. Well done.

He wants to be carefull now he's gone to the press they will probably nick him for parking on the path.

Ouch 5 grand. It still doesent figure though. There must be companies that will cover riders, what happens at the second year? At least you got yourself a bike you can make proper quick should you choose to.

Why is it still funny when you can see it galloping over the hill wrapped in ribbon.

Cor that takes me back, thats in proper good nick for its age.

Nope, identical to the last, even the plug is the same.

I don't understand the logic, spend a couple of grand on a new bike then before the clock has made 3 figures look for ways to make it faster. I don't see why people dont seek out tidy TZR's, Mito's even RG's. A flick through CMM and such shows up enough of em usually even restored they are well under a grand, and you can REALLY make them shift with nothing more than a pipe and some jetting. The late 80's bikes are even free of all the stupid E marked exhausts rubbish and restrictive noise requirements. And you can get the old DT's and TZR's up to 230cc thats like 40 odd hp. Am i just getting old.........

I'd go with the bobbins system too. My TDR nearly fell off the stand i borrowed for the tyre change that used those stupid rubber pads.

Oh and warped discs on the front, it feels like the front wheel is shaped like a 50 pence piece and the more you brake the worse the vibration gets, to the point the wheel can lock/unlock as you are braking in severe cases.

Yikes, when you brake that hard. Especially with those stonking blue/gold spot calipers what you actually experienced was the rear lifting, very slightly but enough for it to want to come and see whats going on at the front. What i think you were actually controling wasn't the bars wagging but the bike waging around the bars and all credit to you for staying shiny side up.

If the engine is stock i really dont think it is something to worry over. By all means swap to the proper pin. Are you sure its a 175 motor, the pin suggests that a 175 top end has been put onto a 125. Nothing to worry about as they are all but identical save for a clutch plate and some carb differences, it might be worth checking the engine frame number prefixes. AT2 is the 125, CT1 is the 175.

Hi welcome to the forum. What exactly do you mean by the 125 small end. Its the same bearing on both 125 and 175. Do you mean the gudgeon pin is shorter?

I'm sure Gas will put me right if i have missed the mark here (he's a bit of a fan)but the Tenere as far as i know is specifically AIMED at european market and the UK gets it to take a piece of the BMW pie.

Sorry cant resist it. Have this one for free........ R6

Hi, modern petrol isnt anywhere near as good as the old stuff. When it evaporates it leaves behind a residue and that unfortunately is very good at blocking things like jets. It doesent disolve in fresh fuel either annoyingly. I would reccomend removing the carb and giving it a good clear through. A piece of kettle flex stripped back to expose the copper wire makes an excelent carb cleaning brush. Strong enough to shift muck and thin enough to fit in the jets and passageways but wont damage the brass and alluminum of the carb. It sounds like the main jet at the very least is blocked or at least restricted.