My DirtBike Wont Start!Please Help!-4 stroke ttr125 kickstart (pls dont bash my bike, just bought to learn on)

Question

I just bought a used dirt bike yesterday. the person that was selling it let us start it up and ride it around to make sure everything was good and it worked great! we brought the bike home and rode it for hours before putting it up for the night. i stalled it a billion times and restarted it and it worked fine (first dirtbike lol). but this morning for some reason it wont start no matter what we do. we did flood the engine at first but we dried the spark plug and weighted a bit. we checked the gap and its good but the spark is dull yellow and not bright blue...is this normal? my father and i did everything we could think of and its still wont work! we are leaning towards bad gas but im kinda worried...i spent every dime i saved on this bike and it would really suck if its something seriously wrong. anybody know what the problem could be? my dad is very mechanically inclined and i know alot about engines and stuff but neither have us have ever worked on a dirtbike before. pls help. thx

thankyou we are going to try emptying the carb like you said - and the tank and starting over with fresh gas. if that doesnt work we will replace the plug and see. thanks for the help!

*like Mr. Knowitall said

Answer 1

Water is heavier than gas and it may have settled to the bottom of the carburetor.

Look near the bottom of the carb for a drain screw to drain the gas from the bottom of the carburetor bowl.

Choke, 1/4 throttle, kick it over.

Or push start it in second gear.

Answer 2

I would first try a new spark plug. The insulator could mess up the spark (cause a yellow spark instead of blue).
If you think you flooded the engine - before installing the new plug, kick start the bike to blow the fuel out of the spark plug hole.
The spark plug cap could be bad or not making a good connection to the wire. Unscrew your cap and screw another cap from a different bike or car (if the car spark plug caps are removable) in.
Before screwing the spark plug cap back on the wire, cut a 1/4" off the end of the wire to get new wire at the end of the high tension lead (spark plug wire).

Next I would check the carburetor.
--Remove the choke to make sure it's working.
The throttle cable is in the center, the choke cable is off to the side a little.
Unscrew the plastic cap and remove the choke plunger. Activate the choke lever and make sure the cable is pulling the plunger.
Make sure the plunger moves freely inside of the carb.
--Check the pilot jet -
Turn off the gas.
Loosen the clamps that hold the carb to the intake and air box manifold.
Spin the carb so the float bowl is facing sideways.
Remove the float bowl (4 screws).
Remove the pilot jet (thin and not in the center).
Hold it up to the light - you should be able to see through it. Clean if necessary.
Good luck.

Answer 3

Make sure the valves are in spec and then check the play on the decompressor cable. I know it sounds like it's not relevant but it is. I had a similar problem right after I bought a used bike. Rode it around for a while then dropped it and it wouldn't start. I was looking all over for disconnected hoses and broken wires etc, someone on this site told me to lash the valves and as soon as I did it the bike started right back up and has run fine ever since. The valves and the decomp were way out of spec, I don't know how it started in the first place.

Answer 4

you will have to take it to tyhe mechanic ..

i ony know that these babies are really difficult to start sometime ,, ,

are u sure there isnt any disruption in the electrical circiurt ... if the connection isnt complete your bike wont start!!

has the juice flooded the engine ?? ...

sometimes this works ... take it on a slope ... turn it on .. start rolling on the slope ... and change the gear suddently ... it worked for me once .. but its risky !!!!!!!!1

i just know abit about the electr ic part of the byke .. . and i always check it first ...

Answer 5

try replacing the plug even through there is stilla spark it may not be enough

you didn't turn the gas off did you?