20 Most Recent 2000 Yamaha DT 125 R - Page 8 Questions & Answers

Well you can always bore out your cylinder and rejet your carb but be warned if you alter your engine there will be a greater chance of reducing engine life

2 and a half make sure the bike's running when u do it the revs should sit between 1 and 3/ 2 2half

alrite mate i had the same problem if you go to www.dtr125.net there is a wirein diagram on there

had exactly the same prob with my dt 125.

In the fuel tank there were two filters that had become a little blocked with small fragments. I replaced both of these, aswell as the petrol tank and now works perfectly.Worth replacing with every service.

Also make sure the amount of fuel to oil is correct because if there is too much oil it leaves a small layer of oil on the spark plug which gets thicker when the engine cools. When you dip the spark plug in petrol and put it back in it obviosly makes a large enough spark to remove the oil, but repeats itself when the bike cools.

Hope this helps

Andrew

Ok, There in itself is a problem? Sounds like the carb is feeding too much fuel,  try this first !! kick the bike over and let it idle go for a spin and take a plug remover with you , when the bike stops , take the plug out and inspect its condition , bare in mind that the plug will be hot so leave the gloves on !, if the plug is wet , your needle and seat will be worn and will need a rebuild, if its dry , don't mix your fuel anymore and use the tank, you can still use the same oil so don't worry, now empty out the tank and put straight fuel in , there could be a chance that the oil hole is blocked since you don't use it so might be a good idea to inspect the hoses first before doing anything ok?
Good luck 

most four stroke engines take a 35-1 ratio.

Here is the manual which may be of help. Not certain if you have a small window low down in the engine that shows oil level or the oil filler has a dipstick...but the manual will have oil amounts which you can measure and refill the crankcase with after you drain the old oil.
rate me please if this is useful or helps your problem.... thank you.

http://freepdfmanual.com/search/2000+yamaha+dt+125+r+manual

Is your gas 93 on up? Is your air filter clean and oiled up? Is it two stroke with oil&gas mixture right.

hello
if im showing the right diagram. the carb on your bike as an oring that seals off the float valve seat. i would pull it out and inspect it. another little trick is to hook up fuel to the carb with the float bowl off and push up on the float and ensure that it is sealing. cause this very much does sound like fuel is bypassing the float valve assembly. really that is the only way you are getting fuel into the crankcase. and also is consistent with it running so rich. hope this helps. thank you.

Get a BRAND NEW plug and recheck for spark. Be sure plug is grounded to engine. By the way, FTjoe (above) has some very good questions. The sator is not involved here. The dealer can check the CDI usually for free.

if plug is wet or sooty check air filter and replace if it is dirty,also check that choke is opening fully.If plug is fouled you may need another one,

Need more info...if you have a multimeter connect it to the battery while engine is running? Is it 1-2volts over battery voltage?

i know this sounds stupid but change spark plug and check lines for choke the line might be pinched and closing the hole and it might have flooded how old is it?

Pick up the phone and call the dealer. Barring that, drain the oil then put one quart in the gear box. Now check the oil dipstick. Add more oil untill it reaches the midpoint of the cross-hatched area of the dipstick.

If it runs at all then the problem is likely to be the carb. Drain it and clean it and also remove and clean the water trap bowl on the fuel petcock where you turn the gas on and off.

If I understand your problem correctly this may help. There should be a spring just a bit smaller diameter than the slide that mounts between the top of the slide and the bottom of the carb cap. No spring means no snap-back. I am assuming there are no kinks in the cable and the cable was routed correctly when installed. Lots of times if the cable is not routed properly the gas tank will "stretch" the cable when the tank is re-mounted. Route the cable properly and the problem goes away..... As far as the slack in the cable, there is a an adjusting screw on the top of the carb (where the cable ends) and an adjuster screw at the hand throttle also where the cable ends. Some bikes have an extra adjuster mid cable but I don't think yours does, (working from memory here). If none of the above work then my guess is that the parts counter handed you the wrong part.

Not much information in your question so here is the scatter gun answer. Do you have spark? Is the spark plug fouled? If the fuel petcock ( gas valve ), has a small bowl on the bottom then remove the bowl and dump out any trash and water that it has collected. Next look at the bottom of the carburetor. Does it have a screw on the bottom or on the side of the float bowl? Turn off the gas valve on the tank then remove the screw and let the float bowl drain any water and trash away. Put the screw and petcock bowl back in place, turn the gas valve back on and see if it will start.

This sounds like pre-ignition, ( also called 'detonation' and 'engine knock' ), Carbon buildup on the piston crown gets overheated and then causes the fuel to ignite before the spark plug even fires. This pre-ignition is VERY hard on the piston and crankshaft bearings. You will need to pull the cylinder head and de-carbon the piston and cylinder head..... but I would first go to the dealer and buy a spark plug that is one step colder than the stock plug the manufacturer supplied when the bike was new. Spark plugs control the cylinder temperature, colder plug = lower head temp = less or no pre-ignition. Problem solved? If not, then go to a higher octane gas. Problem solved? If not then install a lower heat range thermostat in your water cooled engine, i.e. go from a 180 degree thermostat down to a 160 degree thermostat.

Hi Ma_beveridge,

I guess ,since its 10splines you ought to fit in 5 steel plates ,just make sure that no steel plates come into contact with each other except with the clutch plate in between them.

Hope this will help .

GOOD -LUCK.

Knight

Is it not engaging, or not disengaging? Does it just slip when you put it in gear and let out on the clutch? You can try a clutch adjustment, but may need to look at the clutch discs themselves.