Cynic

Its one of the first things to check on a 2 stroke, the plugs have a really hard time and its worthwhile having a good KNOWN plug for emergencies, new ones can be dead right out the box. The one you remove the next time you service the bike, keep it somewhere secure as a get you home measure. Saved me walking more than once.

Hang on!! :lol:

Ahhh right, the dreaded big bore. You cannot just bang the different ig on for more revs, 2 strokes don't work that way. The carb and pipe on a DT are designed to give a better mid range than the rd. Megga rpm will kill it quick too. The extra mass of the bigbore piston will also put extra stresses on your bike. You will be quicker if you go up a couple of teeth on the front and maybe even drop a few off the rear, then shift in the torque of the bigbore, ride the midrange and you will have a bike flexible enough to murder an RD on a twisty B road. If you are trying to catch them on the bypass, don't waste your time.

After replacing THE powervalve cable, whats the other one like and how freely does the pv opperate, and is the motor opperating ok too. It takes a lot of power to bust a cable, more than the little pv motor is really meant for. I would give it more than a cursory look.

None that i know of. They both make about the same power in about the same way. Why bother? They are both CDi.

Coming in at a completely different angle here, have you checked the oil pump is working OK? To me this sounds like the engine going tight. It could be delivering short quantities at higher rpm. Causing the piston to pinch slightly at higher rpm. I'm happy to be proved wrong but if the electrics are messing about cos they are getting hot they dont normally fire straight up after its cut out, you have to wait a bit first.

What bike manufacturers generally do is have the indicator indicator(you know what i mean) earth through the side that is off as there is not enough power running through the lamp to make the indicators on the other side flask. Led indicators need a fraction of the normal amount of electric to work and the earth current from the dash lamp is more than capable of lighting all of them like hazards on a car. If you do whip the dash lamp out dont forget the MOT man will want one in place and working correctly at time of test. Otherwise yes it should fix it.

Hmmm, your pictures are upside down, the bike is a 1978 DT175E, US specification(or used to be) bike. Can't help with the colour though.

So you have led indicators yes? As a temporary measure take out the indicator light in the clocks. If that fixes it you need to get yourself a couple of single line rectifiers, like the ones on a DT175, pop one in each wire to the indicator bulb in the dash and (providing you fit them the right way round) problem sorted.

Close Andy, the MK1 LC and the MX's share the same chassis and swing arm though, including the forks etc. The tank/seat and bodywork are different. You really don't need to mess with a new carb, the VM carbs used on the DT's are pretty idiot resistant. An overhaul kit from motocarb (think thats what its called) will get you running lovely if there is a serious problem with the jets. Strip out the carb again and run all the jets through with some fine copper wire, kettle flex stripped back is good. The copper doesent damage the brass but is man enough to shift what can be surprisingly stubbon particles of cr@p. A particular favorite is the idle jet in my experience, although yours is running ok at idle so your ok there. The fact that it dies at a touch of throttle means the main jet needs looking at, and of course the needle height. I may have missed a mention of it somewhere but you HAVE put a new plug in. 2strokes are incredibly ficke when it comes to the plugs.

Not always, sometimes the lighting circuit charges the battery when its off. I'm with GAS on this though, 3A fuse is a safe short circuit current so you are looking at a real world max of 1A continuous and that will include stuff like battery charging. All you really need to do is make sure the battery is in good nick and be certain its fully charged before your epic . With the capasity of modern sat nav batteries you may do most of your ride before the sat nav is even drawing any real power. My sat nav will happily run from the PC USB plug used to download new maps, that is not going to stress any motorcycle electrics no mater how marginal.

Why remove protection if you don't have to. DT175's have both, i know its a dirt bike but i can see no reason for not fitting them on the XS, they should sit ok under the gaitors, just warm them up a bit or use some wasing up liquid to get them on.

+1 Worked a treat on my DT forks, use a heat gun (this cannot heat the metal far enough to do damage) and cook em good. Smoking the oil is a good sign and they will come out very easily.

What happens if you pull the choke as she starts to die out. Is the plug good Airfilter fitted and reasonably clean Exhaust not too coked up. My first suggestion would be the main jet blocked with a bit of rubbish or possibly float height. I'm assuming we are talking DT125MX not DT125LC. Although it doesent really matter all that much they are pretty similar.

I thought you said yours and OG's bike shared the same pv, its just controlled different. You coulduse the newer stuff if thats the case just make sure the servo and the servo controller match. The controller only uses the taco feed to trigger it. Although i would try to find a real early unit as they were never part of the restrictions.

I have got to change the exhaust gaskets on the tdr so i could take some shots and measure up, wont be this weekend though (i think the exhaust mount is coming from japan via pushbike). Have you got some decent shots of yours (missus) and some measurements so we can compare (oh behaave).

Yep, i generally hang on to the manuals for bikes i've had. Dunno why. I still think its worth a look at a TDR/TZR 250 powervalve. They are very different if that picture that went up a while ago with the piston strike is anything to go on.

I think its saying "I work in an office and it doesen't come up in the options on my computer. Pop along to your dealer and let them say after charging you an eyewatering amount of money for the privelage. If its of any interest the 350book i have shows the cables crossed and the valve should be closed when the engine is started.

Right, this is lifted from my manual. When i mention the colours and the terminals, the text seems to assume you have it in bits. I would take it you can do these checks from the regulator position. First you have to disconnect the A(white) and F(green) wires The white is from the Armature circuit and the green is from the Field circuit. Ground the F (Green)to the E (black) with a jumper wire. Now connect the positive terminal of your multimeter (expect around 14v) to terminal A(white) and ground the black wire from the meter to the engine. UNDER NO CIRCUMSTANCES RUN THE ENGINE OVER 2000RPM OR YOU MAY DAMAGE THE SYSTEM. The irony of the next statement is not lost on me but i didn't write it. Run the engine at 2000rpm?? and you 'should' get 14v. Reassembly is the reverse yah yah yah. As i said at the top i havent done this myself but that is the instructions from my manual. A good battery is also a given but you say it starts so i take it thats ok. Hope this is a help....

Depends if your name is Gordon?

Ok hows this for a theory. OG, yours is an import from a market that is not as restricted as ours, so the powervalve is opening up to give the full fat performance that just requires more tuning with the carb and such to get? Vez Yours UK? Then we have the exhaust port capable of considerably more performance than the law allows so the bike is down jetted and the port timing is tuned to a more relaxed peak performance but giving you a smaller exhaust port area for more mid range performance and bugger the max?

Nothing wrong with that my friend. 2strokes have a very definite power band, while its not as large in the 100cc, its still there and you should feel it if the engine is in good health. The down side is that the power stops as readily as it started, reving a 2stoke for all its worth will get you nothing but bills. Listen and feel how your bike runs, around 750 to 1000rpm shy of the redline you will more than likely feel the 'turbo boost' wear off. At this point you should be changing gear for best performance. Or if she goes that well in top roll off the throttle as you are just wasting fuel.

Just a thought here, did either of you run the engines over 6 grand? I'm just wondering if its not to do with emisions. We know resonance is used to keep the charge in the cyl, there is no reason why you could not use the valve to reduce the amont of material escaping into the exhaust in the first place. Then when you are past the 'green zone' (lame but what can you do). It opens up to allow the power. I take it MaDs bike is no slouch?

So how do the 4 ositions of the pulley affect things. I looked at my TDR earlier to see how that worked but i have to take the exhaust off to see. TBH i have to take the exhaust off to do just about bloody anything.