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

Check your fuse, stand switch, kill button, neutral switch and check for broken wires, ..........................

What happens when you turn the key?
Do all the idiot lights light up?
Does the headlight come on?
Do the brake lights work?
Does the horn work?

Does the starter or solenoid click?
Does the starter grunt and the lights dim?

Does anything happen?

Can you kick start it?
Can you bump start it?
Can you jump-start it?

Martyn

-- Edited by Cubber on Wednesday 19th of October 2011 08:31:54 PM

Rather than clicking and pasting the whole article, take a look (and read) the pertinent points here:-

CLICKY THINGY

It leads you through all that is common with ANY motorcycle refusing to start.

Please start with the easily accessible things like fuse, switches, safety contacts, etc. and check your battery is fully charged.

A quick look at the wiring bike's connections would be good and check that there are no frayed/shorting wires anywhere (particularly around the headstock).

Patience is a virtue when looking for a needle in a haystack!

Martyn

Definite improvement, methinks.

Seems to point to either a bad earth somewhere or a fusty connection on the starting system.

Why don't you start at the starter button on the handlebar and squirt WD40 in it. Then follow the wires from the switch and find a connection (cable run or solenoid or relay or switch) then take the connection apart, clean the metal bits and coat them in Vaseline before re-connecting.

Do this on all the junctions, spade connectors and bits and bobs. Don't forget the safety switches like side stand, neutral and kill button.

Do it methodically - and you will find the culprit eventually.

Good luck.

Martyn

Result 

I have made this thread a sticky as it has proved so useful!

Brian

Popped the clutch on a hill, started, rode briefly. Now it won't hold an idle, the headlight flickers, and won't start without popping the clutch 

Sounds like an electrical problem, check the battery and connections first

Have you downloaded a manual Yet, it's for the blue one

Instant Manual Download for the Blue TTR only.

Good Luck

Turns out a fuse had blown. Easy $10 fix.

On Wednesday, I was coming home from work on the bike, for some reason I wanted to try a top speed run, I was screaming along at 152km/h, not actually going that fast, but the clock was reading that. As I started to slow down, I knocked the throttle off and started to apply the brakes, the engine then revved to the moon. I tried whacking the throttle open and shutting it properly by hand again to no avail. I then knocked the kill switch and pulled up off the road. I pushed it home, because I was only about half a mile away. By the time I got home the engine should have cooled down a bit. I tried starting it when I got home and she wouldn't go again. I had some dinner and went out to try it again and she still wouldn't start.

I assumed it was a carb problem, so Thursday I stripped the carb and cleaned it, I noticed that the little rubber boot between the carb and the intake was split, so could be sucking air in. I have a new one ordered, as a temporary measure I gaffa taped around the boot, to test my theory. She still won't go, you can bump start her but as soon as it drops down the revs the bike will die again. When it's running she lurches a lot, the revs are very erratic and the throttle, which is normally very smooth and shuts very fast, becomes really stiff to turn and then won't snap shut again. Yet, engine off, the throttle is as smooth as you would like???

Friday, I didn't fancy touching her and sat and had a think. Saturday, I wondered if the timing had somehow jumped, perhaps the high revs put extra stress and the chain and it jumped a tooth, which would explain poor low speed idling yet the pulling like a train if you can get the bike to rev past mid revs, which she does if she doesn't die on the way up. The timing was still fine, and I checked the valve clearances while I was at it, they were at the upper end of within spec. I then wondered if the rings had somehow broke or something, I didn't take the head off, but I turned the engine over from the flywheel/timing mark side area thing? I was looking to feel for any tight spots in the bore, I think about half-way up/half-way down it gets tight, but by such a minuscule amount it's hard to identify. So that brings me back to a fuelling problem again. I did notice that the plug was quite black, indicating a very rich mixture, again pointing towards a fuel problem.

I don't understand it and without tearing into the engine I can't be sure what's up. I rebuilt the top end about 3,500 miles ago, it should last longer than that shouldn't it?

Please help,
Adam

I would check condition of throttle cables for fraying and routing as a precaution as u mention stiffness in operation .The split boot would not help and probably explain your oily plug .failing that I would go back to the carb and retrace strip rebuild double check all is correct. As mentioned rule out the simple first 

It's not cable related, I oil the cables regularly, I cleaned the end of the bars, and lubed up the throttle housing. I lubed up the return spring on the carb, and re-stripped and built the carb again, everything is still fine. I don't have a compression tester, but I knew about the thumb trick before, still plenty so possibly not rings but still worth bearing in mind, I think my mate across the way has a proper compression tester. Also the throttle is only stiff with the engine running, it seems to flutter as well.

I ferretted about with her on Sunday, I re-taped up the intake stub, smarter with some electrical tape, not permanently but just while my new stub is on order from Yamaha. I managed to get her running, roughly, I turned the idle all the way up but it still sounds like a normal tick-over, albeit with much coughing and farting and blue smoke. I changed the plug, the old one was all carboned up and I just couldn't justify the time needed to clean it when I can get a new one from my mate for 3 quid, he works at Halfrauds.

Interestingly, I discovered that on Tuesday, when I was on reserve when I got to work, I was given some fuel from a jerry can. There is a fresh petrol, fresh diesel and then contaminated fuel, the diesel and petrol are markedly different, but the mixed and petrol are in identical cans... see where this is going yet?

It turns out they think they picked up the wrong can. Their hearts were in the right place, try to save me a few bob on fuel, but possibly costing more, I'm going to make some labels for them tomorrow.

Would some diesel running through the engine cause this to happen? I never noticed anything wrong with the bike on Tuesday evening or Wednesday morning.

About to drain the tank and chuck some fresh fuel in the bike tonight, let you know how it goes.

She is very ill. I swapped the diesel out for petrol, god knows where it's going to go, back to work and disposed of I think. I have no idea why they keep that stuff knocking about, it's no good in either petrol or diesel.

I think I'm going to run some high octane fuel through the bike for the next few tanks, maybe try to combat the diesel a bit, even at 1.40 a litre, she only holds eight so I think the extra cost of the better fuel should be outweighed by the advantages it brings.

Why does she pull like a completely different animal though at high revs? I don't want to sound too dozy, but she reminds me of a proper 'crosser when she gets going, hardly any engine braking and really grunty. I can't see diesel helping that out. Maybe just getting the carb cleaned twice a week combined with the pipe just unlocked a couple of extra ponies, combined with riding the Vara 125 to work again recently, makes her feel different. I don't really know. More playing tomorrow, I think.

Got her going, with another clean of the carb, a re-packed silencer and a new intake stub thing and fresh petroleum. Took her for a spin around the block, all was well so I put the rest of the bike together again, side panels and seat, chucked my jacket on and left for the open road.

50 miles later, the problem comes back, she starts revving on her own again, not a lot, but just about 2,500 RPM, at a guess. I pulled over to have a look, couldn't see any problems with the throttle actuator sticking, it was returning back to the idle adjust screw nicely, the cables weren't kinked, the throttle tube wasn't sticking. I carried on again just on the new idle speed, I then pulled over while leaving the engine to run still, I noticed fuel leaking from the bottom of the carb, near the section with the diaphragm inside. Is that the pumper part? I didn't notice any tears in the diaphragm but what could cause it to keep pumping some fuel in to keep the bike revving a little bit? I assume that's what is happening to cause this issue.

Any help, will be very gratefully received.

Starter wasn't working so i fixed that with a new starter relay. Now the starter works but wont turn the motor over. I pulled the starter cover off and held the gears in and pushed the button. Gears turned over but motor wont turn over. Is this the starter clucth?

It doesn't have kicker us model. Starter is factory. What would i need to look for on starter clucth if not in gauging.

I can move it but its not easy to move.

No its the same both ways. It's tight both ways.

Im working on pulling it off. Trying to get my hands on a puller.

You are the best Brian.