Question about 2003 Yamaha DT 125 R

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My dt125 r 2003. it willn accelerate in the 1st 3 gears in the power band. but the next 3 gears is holding back as if it missing. i bought it couple of days ago and was doin it till i put fresh petrol in it. but has started doin it again help if u can please

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SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

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Posted on Jan 02, 2017

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SOURCE: 1st gear issues

How do I put this? Yes, you have a bent shift fork. And, yes, they can get bent in a fall, a dump, a drop or whatever terminology is used. The fork engages into a collar on a gear that slides left and right, (slider gear). Large "pins" called "dogs" are cast into the side of the gear. The dogs engage into holes in the side of the gear you are shifting into. Question: What happens if the bike drops on the clutch side and the shift lever is forced down, moving the slider gear to engage first gear even though the holes in the side of first gear are not lined up with the dogs on the slider gear? "You get a bent shift fork" is the correct answer. The force of the shifter lever moving the shift fork into the solid parts of first gear, (not lining up with the holes), is easily great enough to bend a fork. That pressure has got to go somewhere.

The repair means removal of the engine and a complete tear down of the engine/gearbox. The replacement of the bad fork is a given. But I suggest you do some preventative maintenance now, while the engine is apart anyway. Replace the sprocket shaft left bearing and seal, both crankshaft bearings and seals, shift shaft seal and the water pump seals. These are pretty low cost items and replacing them will mean you have pretty much rebuilt the engine. Have the dealer check the shift shaft to be sure it does not now have a bend in it.

Go to the site below where you can see a parts diagram for your specific bike. You will select the actual brand, year, model, etc., once you go to the site. Part numbers and prices are also shown. You can order parts from this site. In the event no price is shown on a particular part, the part is not in stock.

Go to this site and you can download a free PDF service manual. Most of the manuals are in English but some are not. There is no way to be sure without doing the download. You can always delete it if in a foreign language.

By the way, you can click on an experts name and see that persons profile.
Best wishes, tombones49 Please top rate this solution. Thanks!

Posted on Jun 07, 2009

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SOURCE: bike starts and runs for 5 min the shuts off and

Try running with the fuel cap cracked open a bit - you may have a blocked fuel tank breather.

Posted on Jun 29, 2009

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SOURCE: The engine loses power when 1st gear is engaged,

This sounds like a broken tooth on the main axle. This would account for the lump in every gear and a power loss due to the axle being bent also. I would change the axle, support bearings, and the gear the axle engages. Check the output shaft for bending also.

This could be bad bearings on the shafts but is is highly unlikely if the gearbox oil has been kept at proper levels. In any event, the gearbox will need to be opened up for inspection.

This image is generic and not specificly the TRX850

Posted on Aug 05, 2009

  • 1124 Answers

SOURCE: Yamaha TW 200 starts but won't run.

If the bike has sat for a long period of time without being run - the gas that is sitting in the carb(s) will shellac.. Then the carb(s) would need to be cleaned and "rebuilt"..

Posted on Sep 14, 2009

  • 112 Answers

SOURCE: No power during acceleration

seems like you make have some debris clogging your fuel line. You may need to replace the fuel filter and clear the fuel hose. The reason that it takes off at full throttle, is because you temporarily clear the clog. Routine use of fuel injection/ carbeurator cleaners is always recommended to prolong fuel filter and fuel line life and prevent these things from happening. Good luck. I hope this helps.

Posted on Jul 22, 2010

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