20 Most Recent 2003 Yamaha DT 125 R - Page 6 Questions & Answers


Hi, Anonymous sorry you can't find the first and best tool you ever bought for your Yamaha despair, not for a mere $0 you can download another one. For more information about your issue and valuable "FREE" downloads that you will need please visit the websites below. Good luck and have a nice day.
https://yamahaclub.com/forums/topic/23188-dt125r-dtr-dt125-oil-pump-problem
Autolube Settings On My Yamaha DT125RE
http://www.motogelnar.cz/manual/YAMAHA/DT125X_RE-05-Service_Manual.pdf
OEM parts for Yamaha
http://www.dt125.cz/download/Owners_Manual-DT125X_RE.pdf

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/gregg_c0ec1df182c7330e


Yamaha DT 125 R... | Answered on Mar 10, 2016


Hi, Anonymous sorry you can't find the first and best tool you ever bought for your Yamaha despair, not for a mere $0 you can download another one. For more information about your issue and valuable "FREE" downloads that you will need please visit the websites below. Good luck and have a nice day.
http://www.motogelnar.cz/manual/YAMAHA/DT125X_RE-05-Service_Manual.pdf
OEM parts for Yamaha
http://www.dt125.cz/download/Owners_Manual-DT125X_RE.pdf
Yamaha DT 125R
http://www.dirtntrial.com/tuning.htm

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/gregg_c0ec1df182c7330e

Yamaha DT 125 R... | Answered on Mar 10, 2016


Hi, Anonymous your power valve may be going south for more information about your question and valuable "FREE" downloads that you will need please visit the websites below. Good luck and have a nice day.
Yamaha DTR Power Problem Not Hitting powerband Help needed motorcycles
DT125 whys my bike so slow
http://www.motogelnar.cz/manual/YAMAHA/DT125X_RE-05-Service_Manual.pdf
OEM parts for Yamaha
http://www.dt125.cz/download/Owners_Manual-DT125X_RE.pdf

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/gregg_c0ec1df182c7330e

Yamaha DT 125 R... | Answered on Mar 10, 2016


Hi, Reece you may have squeaked your top end this is commonly known as "HEAT SEIZE" the piston heats up expands and becomes extremely tight in the cylinder bore and usually occurs mainly on 2 cycle engines right after a fresh top end rebuild, but it can also happen to brand new motorcycles, these are rare instances due to better quality control and education. Overheating failures that cause pistons to seize are many and each one should be carefully diagnosed to prevent future repeat offenders and the usual suspects are:
1. Loose fasteners causing intake or base gaskets to leak or crankshaft seal failure caused by age overheating, or walking.
2. Improper assembly of reed valve gaskets.
3. Improper oil/fuel premix ratio.
4. Broken pinched, or cracked fuel line.
5. Carburetor fuel passages clogged or restricted from stale fuel varnish, ethanol sludge, dirt, rust, or fuel level in float bowl too low.
6. Main jet size too small.
7. Air filter improperly installed, missing or not sealing.
8. Faulty or improperly adjusted oil pump and or cable.
9. Failure to bleed oil pump after running oil tank dry, rebuild of pump or replacement
10. Among the causes of lack of cylinder, lubrication is clogging of lubricator by dirt or waste, obstruction in oil pipes/lines, leaky check valves, leaky pump packing, broken oil pipe/line, oil too cold to feed.
11. Wrong type of oil used in premix or oil tank
12. Improper spark plug heat range (too hot) and or gap.
13. Ignition timing retarded, faulty CDI.
14. Excessive engine load, brakes dragging, clutch slipping, transmission lubricant level too low or viscosity to high.
15. Engine coolant level too low, too old, or improper mixture ratio.
16. Engine coolant pump failure, damage, or passages restricted.
17. Radiator clogged, fins damaged, or faulty cap.
18. Failure to follow proper break in procedures.
For more information about your issue and valuable "FREE" downloads that you will need please visit the websites below. Good luck and have a nice day.
Dirt Rider Magazine
dt125 kickstart jammed and possibly more
http://www.motogelnar.cz/manual/YAMAHA/DT125X_RE-05-Service_Manual.pdf
OEM parts for Yamaha
http://www.dt125.cz/download/Owners_Manual-DT125X_RE.pdf

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/gregg_c0ec1df182c7330e

Yamaha DT 125 R... | Answered on Mar 10, 2016


Hi, Anonymous sure why not for more information about your question and valuable "FREE" downloads that you will need please visit the websites below. Good luck and have a nice day.
https://yamahaclub.com/forums/topic/14538-dt125re-bigger-carb-help-please
Boost Bottle
http://www.motogelnar.cz/manual/YAMAHA/DT125X_RE-05-Service_Manual.pdf
OEM parts for Yamaha
http://www.dt125.cz/download/Owners_Manual-DT125X_RE.pdf

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/gregg_c0ec1df182c7330e

Yamaha DT 125 R... | Answered on Mar 10, 2016


Hi, Dean it would help if I knew the year of your bike, for more information about your question and valuable "FREE" downloads that you will need please visit the websites below. Good luck and have a nice day.
Find the color code of your Yamaha Motorcycle
Yamaha Motorcycle Paint ColorRite
http://www.motogelnar.cz/manual/YAMAHA/DT125X_RE-05-Service_Manual.pdf
OEM parts for Yamaha
http://www.dt125.cz/download/Owners_Manual-DT125X_RE.pdf

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/gregg_c0ec1df182c7330e

Yamaha DT 125 R... | Answered on Mar 10, 2016


through experience i can tell you that dt125 r's are prone to warping heads and even barrels can distort at the studs.get the head and barrel back off and get them checked or skimmed minimally to be on the safe side,i would also leave the thermostat out.

Yamaha DT 125 R... | Answered on Nov 23, 2015


All the Japanese bikes I have owned won't start in gear unless you pull in the clutch lever. There is a small plunger switch fixed to the clutch lever stock (the part that does not move). This switch is connected to the ignition and starter circuits, so when the clutch lever is closed the starter won't turn. Check the bike starts OK when not in gear. If you try to start the bike in gear and it does not start with the clutch lever pulled then the switch is not working. Hope this helps.

Yamaha DT 125 R... | Answered on Mar 04, 2015


Search web for "De Restricting my DT125R" there are several sites. Caution when doing this as over revving the motor can have disastrous results. An use only the best lubes and high octane fuels.

I De Restricted my 1981 YZ125 an she still Runs today.

Yamaha DT 125 R... | Answered on Feb 04, 2015


check for spark to the spark plug if it works, check the carburetor is not a dirty jet.

Yamaha DT 125 R... | Answered on Sep 20, 2014


dirt in the carb , strip and clean ! clean tank also !
low compression , 100psi or more on tester and if less then remove cylinder head and check bore for wear or damage , gasket also ! if damage in bore then a rebore and oversize piston kit and new gaskets etc !

Yamaha DT 125 R... | Answered on Aug 15, 2014


i do not think so this sounds like a motor seizure you will need to take the spark plug out and see if the piston top is alright if it is try to turn over with the plug out if it want turn over then it has siezed up and will need to be rebuilt

Yamaha DT 125 R... | Answered on Jun 10, 2014


must be a faulty tachometer because that bike at 12000 rpm would sound like its about to explode.

Yamaha DT 125 R... | Answered on Apr 12, 2014


Carb no doubt needs a rebuild. Dirt, debris, is not allowing fuel in. Check fuel lines as well. No need to do a part job. Carb ports easily get clogged

Yamaha DT 125 R... | Answered on Mar 30, 2014


Does the bike leak oil, if so fix the leak as 2-stroke engine's fuel supply run through engine casing.
Check exhaust for blockages.
Bike is running lean/rich

Yamaha DT 125 R... | Answered on Dec 10, 2013


Change needle and seat

Yamaha DT 125 R... | Answered on Dec 10, 2013


I would make sure the oil level is not too high. Next I would remove a spark plug and test compression to see whether your rings are worn excessively.Hope this helps.

Yamaha DT 125 R... | Answered on Dec 05, 2013


Only when the engine is not running, alternator should supply power when engine kick started.

Yamaha DT 125 R... | Answered on Oct 31, 2013


try a dealer they may be able to help

Yamaha DT 125 R... | Answered on Jun 08, 2013

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