mckenzie

Ive always like the little Honda v4's, Ive always said I'l have an RVF400, to me they still look up to date, and would piss over alot of other bikes on the twisties!

Is there anyone here from N.I? I would like to get out for a few runs comming into the good weather and was wndering is there a big Yamaha Owners Club following over here?

Well it could be your mixture, but to be quite honest, I havent yet mastered the art of carb tuning, this may help you....... http://www.szocimotoros.hu/download/Basic2strokeTunning.doc http://justkdx.dirtrider.net/printcarbtuning.html

csrtainly 110 wouldnt be a problem, you could achieve 130 plus with the correct gearing and a decent faring I imagine, that is why I'd worry about stopping the bugger lol Can I ask is this machine going to be a road going model? or is it purely for track?

you should try and alter your needle again, if it runs ok when the fuel tap is off then it sounds like its over fuelling

air filter, dirt in the float bowl, faulty ht coil

well you seem to be on the right track, how is it running now?

could be overfuelling, your jetting may be wrong although the plug colour suggests its burning ok, have you checked the position of the needle in the carb?? i see someone has already mentioned that but i guess this is the problem

I dont mean to be rude but you should maybe think of selling it and buying a faster bike, ie a restricted dt125. but I can understand that maybe you like this particular bike? maybe it holds a certain place in your heart (for me its the dt) other than that you can spend money on porting, camshaft reprofiling, new exhaust, race ignition, bigger carb etc, im sure theres a few websites that deal with 4 stroke tuning. have a search and see what you can come up with

haha if these guys where never caught it was the perfect crime!

yep, as i suspected, the worst case senario is a fresh piston kit and hone the bore, although if it has bit in to the barrel it will need a rebore, maybe .25 oversize to clean it up. and you may need to split the cases if there are bits of rings and piston missing. have you instpected the barrel yet? my guess is there will be a few pickup marks on the exhaust side of the barrel, as to the cause it could be your carbuation, ignition problems ie detonation or pre-ignition, or not enough oil getting into the engine. have a look at your barrel and piston and post a few photos up of the damage

I had 1 for the fields about 7 years ago, nippy enough for me at 15 lol

looks like its going to be a wee beuty! that tank looks like it cost a few hundred, are you keeping it polished or painting it? my main concern would be the brakes if your fitting a good tzr motor but i suppose its not carrying much weight. keep us posted

sounds to me like the rings have nipped up, this happened to me with my Italjet formula and my dt. did you notice if there was less compression?

I understand completely, I'm in the exact same position, Im trying to get my dt125x running again as well as my twinshock motocross Rotax project, I lost my job last September and all I can really do is look at them, or clean the clean bits lol

I had the starter off to inspect it and everything seemed ok, apart from a small piece of wire protruding between the gaps of the windings but i flattened it and once i put everything back together it was still turning in the wrong direction. so I've maybe put it together incorrectly? it only goes in one way by the looks of things. I will try again tommorrow

sounds like the waterpump to me, maybe the seals are gone! although if it was sitting for a long time condensation can gather and possibly leak through depending on the position of the piston

If you have the time why not do the whole lot, they arent complicated bike to work on although mine was a later model. looks like a nice project, keep it up

well I thought it might be the starter relay but it seems to be working fine, I'm getting the lend of a meter tonight so hopefully I'l get to the bottom of it

I forgot to mention that sometimes the starter wont turn at all but I can clearly hear the relay clicking when I hit the start button. Everything mechanical is fitted correctly so it has to be an electrical problem, anyone with some knowledge of electrical systems should be able to help, I hope

put some pics up and we'll have a look, look for the engine number stamped on the bottom of the barrel usually on the lower left hand side

The starter motor on my dt125x seems to be turning the wrong way, I cant figure out why since I have not touched the electrics in any way, the only thing is when i was rebuilding the engine after blowing the crank I used a caphead allen screw instead of the standard cheesehead and it fouled the starter gearwheel and when I went to start it the starter struggled to turn the engine over and there was a small puff of smoke where the starter motor relay is located. I checked the 2 fuses on the relay and they are both fine, could the relay itself be faulty? I replaced the screw I had used with the origional and tried again, the motor is turning the gearwheel behind the flywheel but in the opposite direction, what has happened? what else would cause this problem other than some connection being round the wrong way?

i was looking at the same Athena kit, its a 170cc kit and i think the barrel nikasil plated, which is expensive to rapair, but none the less it would be a good way to get a few more ponies, if jetted correctly, and maybe ported you will see 100mph!! i was going to send my barrell to Stan Stevens to port it but I think the 170 kit would be more reliable. the dt 200r/sdr 200 motor is completely different, I know someone with an sdr which is identical to the dt 200r and the crank and barrel/head are different, if you look inside the dt125 crank cases you will find that there is barely enough room for the stock crankshaft so that rules out a stroker kit, the crancase walls are too thin to machine. also the dt200r barrel has the intake manifold on the actual barel rather than having in coming in the crackcase behind the barrel like the 125. hope this helps

the mx125 shares the same rotax engine as the rs125, the rotax engine is a very good engine and is reliable for the state of tune it is in, like any machine..... if its looked after well it makes life a hell of a lot easier

I am thinking of competing in motocross events, Im after a yz 450f and want to know what its like to ride, service and mainly how it compares to the other bikes in its class; rmz,crf,kxf,ktm etc