A forum for owners of Yamaha TTR250 trail and enduro bikes!

shad · Veteran Member

My bike wont start

Cubber · Super Guru

Oh dear - sounds like you're having a problem. cry

Have a look at this CICKY LINK of a previous thread.

Read it all and decide what bit applies to your problem.

Martyn

TT-R250M · Super Guru

As you said that you have no lights, I don't think that clicky thing will help other than the fuse.
If you do not have lights when the ignition switch is on, I would suggest to check-
Battery leads are tight.
The battery to see if it has lost charge? (even though it would still run without the battery given that the rectifier works but the lights would be dim and no electric start).
The 15-Amp fuse (located above the battery box).
It does seem like the battery is flat but there is more possibilities like wiring harness, rectifier/regulator, stator etc..
Not sure what you meant by this bit, maybe you could clarify what you mean...

shad wrote:

as i said i have no electrics what so ever i can still clutch it starts then i get eveything back and my battery is charged as i was riding it ive checked around the battery for broken wires and the like i couldnt see any but when im not as achy( it was a good ride =P) im going to go check it out again

shad · Veteran Member

as i said i have no electrics what so ever i can still clutch it starts then i get eveything back and my battery is charged as i was riding it ive checked around the battery for broken wires and the like i couldnt see any but when im not as achy( it was a good ride =P) im going to go check it out again

it was only a quick check over on the track and really sore atm i dont really wanna pull the bike down so to speak my father thinks it may be the magneto(or part of it)

thanks for the rather quick replys ill check over the things u listed tommorow and tell u hope i dont have to spend money to fix this lol

TT-R250M · Super Guru

shad wrote:
i can still clutch it starts then i get eveything back and my battery is charged as i was riding it
By this do you mean that you can roll-start it and you get lights etc.. back or?
I do not understand the problem you are having but...
When you turn the ignition to the ON position you should have lights etc. This is because everything is running off the battery.
When the battery is flat, the lights will not work when the ignition switch is turned ON. However, when you roll-start/kickstart it, the lights will light up but will be dim.
First thing to do is check the main ground located at the rectifier/resistor is grounded correctly. Unloosen the bolt and tighten it back up once the terminal is clean. This bolt earths the regulator/rectifier along with the other bolt so make sure these bolts are not rusty and have a good connection. The other earth to check is at the ignition coil, check this also.
Now...
If you do not have 12~13.5-VDC at the Orange wire leading to the ignition coil when the ignition and ON/OFF switch is on, there may be a problem with your battery . If it is flat it may be a faulty rectifier or AC magneto. The best method I have found for checking the rectifier is to unplug the 15-Amp fuse (located above the battery box). Now using a multimeter on 20-V range, test the red fuse wire leading from the rectifier (not the wire leading to battery) to see if it has 12.6~13VDC when the engine is cranking. If the power is fluctuating, or the charging voltage is over 15-VDC, it would suggest that the rectifier is at fault. If there is no power at all or there is only 1~6-V it suggests that the AC magneto is at fault.
If all this checks out and the bike does not start but everything else is okay (lights etc..), the AC pick-up could be at fault. You would need to test the white wire with a red stripe and the white with a blue stripe leading from the AC magneto to ensure you are getting a AC small pulse when cranking the engine. You will need a multimeter that can test AC current in the 20-V range and a second person for this if you cannot use the electric start.
If the electric start still does not work but you have lights etc., I would suggest to try all the things mentioned in Martyn's CLICKY LINK.
As mentioned though, it will run without the battery if the wiring harness, rectifier and AC pick-up is working correctly but the lights will dim and the electric start will not work.
Oh, if you raise the bike on a sturdy stand you can put the bike in top gear (5th or 6th) and spin the rear wheel rather than using a kickstart or electric start to crank the engine while testing. This requires two people (obviously).