Question about 2003 Yamaha DT 125 R

2 Answers

Hello ive recantly replaced my pistons and rings on my dt 125. i have been told it was the pistons that was stopping my bike from running, but now that i have changed them my bike will still not start. can you help me out and give me some problems that it could be thats keeping it from starting. thank you...paul...

Posted by on

Ad

2 Answers

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • Master
  • 3,567 Answers

The first thing to do is get a new stock spark plug. Hook up the plug wire then have someone kick the lever while you hold the metal side of the plug against the bare metal cylinder head looking for spark while the starter is being kicked. If no spark is seen, find out why. Use a meter to check the handlebar and side stand switches for proper operation. How good is the battery? Are there any wires abraded or disconnected? Has the pulse generator, coil or CDI gone bad?
If spark is present, Be sure the air cleaner is clean. A dirty filter restricts the air the carb needs. Okay, you have spark and you have air, now you need gas. Start by draining the carb. Condensation from the gas tank can get into the carb float bowl and build to the point the carb is feeding only water into the engine. Engines don't run well on water. When starting the bike, do not go nuts with the throttle. Every twist on the throttle sends a shot of gas into the engine. Too many twists can flood the engine. Your bike is water cooled. Good gaskets/seals are needed on the cylinder and head. At this point we will assume the coolant system is not leaking.

Posted on Mar 22, 2011

Testimonial: "thank you so much for the advice, ive checked everything that you've mentiond on ur list, but it is still not starting, can u sugest anything els.thnx"

  • tombones Mar 23, 2011

    Do you have spark??? New plug? clean air filter? The gas IS turned on isn't it? Check each fuse with a meter, one could be blown. The kill switches are working? Check for loose and disconnected wires. If the bike still has no spark, take the bike to the dealer and ask them to check the coil, pulse generator and CDI. If you do have spark, get a can of spray starting fluid and spray into the air intake ( air filter ) then try starting it.

  • weepettinger
    weepettinger Jun 16, 2012

    SEE IF ur earth wire on ur bike is contected it happened to mine before but no i have changed my pision and head gasket and now it will not start

×

Ad
  • Level 1:

    An expert who has achieved level 1.

    Corporal:

    An expert that has over 10 points.

    Mayor:

    An expert whose answer got voted for 2 times.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 19 Answers

Check your ex it ma be plugged coment on bike nothing to do with spark I did not give any info on spark matter just why it might not run and rev.

Posted on Dec 18, 2011

Ad

1 Suggested Answer

6ya6ya
  • 2 Answers

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

Hi,
a 6ya Mechanic can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repair professionals here in the US.
click here to Talk to a Mechanic (only for users in the US for now) and get all the help you need.
Goodluck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Have i broke my bike by moving power valve whilst running now its not starting


Hi, Anonymous I don't think so probably just flooded remove the spark plug kick it over a few times squirt some Brake Kleen or starting fluid on the plug and blow dry with compressed air and reinstall and you are good to go 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.
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 125 2003
http://www.dirtntrial.com/tuning.htm

Apr 30, 2014 | 2003 Yamaha DT 125 R

2 Answers

I was given a 2000 yamaha DT 125 and i was told needs regular fuel and 2t oil but i dont know the combination or how much mix to the gasoline please help


Are you sure this is a DT 125 as with this particular bike it is self mixing there should be a separate tank by the handle bars just under the front plastics opposite the water tank this is where you fill it with oil then just put gas in the gas tank and it will mix it self you do not have to do anything else do not put oil in the gas tank with the gas mixing would usally be dirt bikes or really old bikes only

Mar 12, 2013 | Motorcycles

3 Answers

I have a dt 50 which i have put a new piston and rings in.Now the bike does not run properly.It starts with the choke on full ,picks up revs ,back fires then dies,Is this a fuel or CDI problem.Help please...


cud be a combo of both-running rich from carb or weak spark--chec plug and cable for wear and resistence or test ign unit--may need jet ajust--breakin procedure is the same as new bike--get a maintenance manual-sayonara

Jun 21, 2010 | 2000 Yamaha DT 125 R

3 Answers

Hello, i have a yamaha dt 125 r motorcycle and I have a problem release the front chain gear because the whole engine turns while i am trying to remove the nut from the gear.W hat should i do?


Did you try an impact driver? How about putting the bike in low gear? If not, just get a breaker bar on there an whack it with a brass hammer. I'm pretty sure it is a right hand thread. Hope this helps.

May 14, 2010 | 2004 Yamaha DT 125 R

2 Answers

Yamaha dt 125r power valve


Your barrel? LOL. Sounds like the valves need to be gone through. I would suggest taking and valve train apart and put it back together correctly then go from there.

Aug 07, 2009 | 2003 Yamaha DT 125 R

1 Answer

Hyosung RX125 I have had an oil leak ever since I dismantled the engine last month. There was a slight knocking, however I went out on it last weekend regardless. The bike started to lose power after 2...


Is your bike making blue/blueish smoke while running? From the stuff you told us, it is either worn piston rings or worn valve seats, but i would personaly bet it's the valves, because the knocking sounds would be the valves being severely out of adjustment, leading to a huge loss of power and many noises. Hope i helped you :)

Jun 16, 2009 | 2002 Hyosung RX 125

2 Answers

DT 125 2000 Very poor starter. Stolen recovered so no ignition


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

Apr 15, 2009 | 2000 Yamaha DT 125 R

1 Answer

Cogs in a gear box


hi karen, that is right, i do have a DT 125 myself and same thing has to be done.

Usually this is balance the engine so that the moving parts will move to a limited place. this is also to avoid further block damage when the piston is moving up and down.

Jan 01, 2009 | 2002 Yamaha DT 125 R

Not finding what you are looking for?
2003 Yamaha DT 125 R Logo

331 people viewed this question

Ask a Question

Usually answered in minutes!

Top Yamaha Experts

dhnguyen

Level 2 Expert

281 Answers

vince

Level 3 Expert

899 Answers

Steve Sweetleaf
Steve Sweetleaf

Level 3 Expert

1147 Answers

Are you a Yamaha Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...