20 Most Recent 2002 Yamaha TT-R 125 Questions & Answers

intake .005-.006 exhaust .007-.008

Remove the water trap bowl at the bottom of the petcock, (gas valve). Is there any water or trash in the bowl? Drain a cup of gas from the tank. Is there any water or trash in the cup? Dump it, clean it and re-mount it, ( not all bikes have a water trap bowl ).

Drain the carburetor. There should be a screw on the lower side of the carb float bowl. Remove the screw then replace it after the fuel drains. Turn the gas back on and wait a minute for the carb to fill with gas. Install a new stock NGK spark plug and try to start the engine. If the bike doesn't start and run properly then shut off the gas and remove the carburetor from the engine.

Remove the float bowl and clean the entire carb with a spray carb cleaner from the auto parts store. Wear protective goggles to avoid getting spray in your eyes. Spray into all the little airways and fittings in the carb. Remove the idle screw and the air screw on the outside throat of the carb and spray into the screw holes as well.
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Be sure to put these two screws back in the same hole they came out of. IMPORTANT > do not tighten these two adjusters down. Only screw these in until they LIGHTLY seat. Now turn each adjuster one and one half turns outward. Put the rest of the carb back together, clean the air filter and install the carb. Let the float bowl fill then start the engine. This process should get you back on the road.

If the above does not solve the problem then pull the slide out of the throat of the carb and move the clip on the jet needle one notch lower.

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it could be that when u are riding the bike that u are loosing air maybe because the rim is leaking when u hit bumps. this happen to my sons bike and I solved the problem by using a inter tube.

On the left side of the bike on the engine case there will be two large nuts. The smaller one acts like a peep hole that allows you to see the fly wheel. Align a mark that looks like this ( 'T ) to the notch in the threads. WARNING MAKE SURE THE BIKE IS AT TOP DEAD CENTER COMPRESSION! Do this by looks through the spark plug hole and make sure the piston is at its highest point. Once you do this look at the cams. There should be small punch marks in the cam gears. These punch marks need to be aligned with the gasket surface. To check final alignment rotate the engine with the cam cover off and the cams BOLTED down. Make sure the cam tensioner is installed properly as well.

Just give some tap on the carburetor with some screw driver this will help if the float is stuck in the carburetor if the problem is not solved then change the float needle in the carbutetor

Make sure your spark plug is not fouled and the gap is correct, also air filter is properly cleaned. If it still wont idle, locate the idle adjustment on the carb. There are 2 screw type adjustments there, one is the idle/air screw and the other is idle adjustment which is the one you want. Start the bike and warm.it up, slowly turn the idle adj. Inward like tightening a bolt, periodically give the engine a slight rev and let it idle.down. Do this until you reach the desired rpm you want to idle at and your finished

I had the same bike for 3 years and it wouldn't start when it was too cold outside under--about 33-37 degreese--it wont start.
---how cold is it where your trying to start it--

i know this bike like the back of my hand

you can email me @ [email protected]

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Have you checked the vacuum lines? It can be a vacuum supply issue that's why it bogs down. You may want to replace soft vacuum hoses.
Hope this helps and thank you for using FixYa! Have a good one.