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

Hi mate repost this in repair maintenance section of forum for more help sounds like you may have a sprag clutch problem and regarding fuel flow is fuel in tank above reserve which i beleive is about 1 ltr of fuel .post in other section for more help 😉

Mine was doing similar when the sprag clutch died. My thread there: ttr250.activeboard.com/t61048065/aftermarketsubstitute-sprag-clutch/

Or, to do it correctly, see here: ttr250.activeboard.com/t55558020/sprag-clutch-one-way-assembly-replacement/

 

However, I am not sure. 

-- Edited by bosi on Tuesday 17th of November 2015 09:03:55 PM

Or take the tank off and lay it on its side with petrol tap upwards (or lay the TTR on its side but watch your back picking it back up!) and take out the tap to check the filters are clear.

Fuel is drawn in from the RH pipe on main and LH pipe when on reserve.

The other possibility is that the gasket in the switch has broken up or something is blocking it. It's a simple job to take the two screws out and check.

Brian

There's defo fuel in the tank but not a lot so that will explain the reserve only fuel! Need to fill the tank and see if that's better ( I'm sure it will be)

Just looked to order a sprag but errored my order so will do it again tomorrow. Anything else I should order too? Gaskets etc?
Looks like a simple process to change from the great guide though I'm sure there will be problems along the way!

Thanks all for your help

As long as I can keep my repair bill under control I don't mind. I've got the bike to do up and to learn on and hopefully one day soon hit those trails!

Needs new rear wheel bearings at some point soon too and no doubt a few other little things.....

Good advice above you will need to inspect all other associated componenents as a failing sprag can cause damage to starter motor splines and large and small starter gears you dont want damaged gear teeth ect .hopefully you will be lucky and caught it in time cannot stress how important it is that all teeth mesh correctly to prevent damage and further expense . A flywheel puller and a torque wrench are a couple of essential tools you will need too 

Additionally if I put the bike in gear and hold the clutch in it will not turn over at all, is this Normal for a ttr

Could the engine be ceased up ??

MikeBarnacle wrote:

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Additionally if I put the bike in gear and hold the clutch in it will not turn over at all, is this Normal for a ttr

Could the engine be ceased up ??

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Sounds like the clutch switch (fits on the clutch perch) has failed Mike

The CDi won't let the starter turn if the engine is in gear without the clutch lever pulled in and actuating the switch.

Have you pulled the plug to check you have compression? Simple check is to put your thumb over the plug hole and turn the engine. It should push your thumb off the hole with a bit of force.

Whilst the plug is out put it back in the cap and rest the body of the plug on the engine to earth it. Crank the engine and check you have a regular good spark.

If all good then you probably need to get the tank off and check the cam timing is correct and that the valve clearances are within specification.

Have you undone the carb float bowl drain screw to check there is a good flow of petrol?

Does it fire if you squirt a bit of carb cleaner (or EasyStart) into the intake?

As Martin suggests, you need to make sure that battery is fully charged so that it turns the engine quickly to give the best chance of blowing out the cobwebs and getting it started.

Brian

Yep, I had tried a few times to get the bike running and yeah the battery was probably a bit drained to be fair. I've tried a battery of my xjr and it did fire up!...... How ever it's only been in nutrel so let's see what happens tomorrow when I put her in gear for a ride down the drive.
🙂

So having ridden the bike for about 9 hours now she's decided to conk out on my leaving me with a casual push home for half hour!

Battery fully re charged after drain it, I seem to get a "pufp" noise from a part of the air in take...see picture. It only happens if I try a little throttle after a few pushes of the button. (Kicking out 13.3v on the meter I bought today)

Ive been back in and checked sprang clutch and all seems fine and dandy in there! 

Can't access the drain on the carb some numpty has rounded that off in the past by the looks of it! 

Not sure what else to try, the bike does turn o just won't fire again!   did fit a new plug previosuly when trouble shooting, I've checked that and it's fine.

lights still work 

trying to think what else is useful........

 

apart from  really wanted to fix it by thursday  a ride over hartland way!

 

one thing worth mentioning is I did run out of fuel yesterday too but switched to reserve and yeah I am back to "normal" again now.

 

any help greatly appreciated

-- Edited by MikeBarnacle on Tuesday 29th of December 2015 08:08:13 PM

-- Edited by MikeBarnacle on Tuesday 29th of December 2015 08:10:23 PM

The pumpf noise seems to be a release of air from between the carb and the air intake.

Yeah it cranks at the same pace, compression seems to be good, I took the plug out and pressed the ignition, it gave my finger a good push!


There is a small bowl that seems to come off air in take that had a nasty smelly milky water in it, I've drained it off...wasn't much but seems to be something worth removing from the air system. It's also worth nothing that there was a bit of it inside the large air box (not sure any of this is relevant)

 

the he bowl is just lower to my finger (right in image)

I dont have any but will grab some tomorrow, where do I squirt it? (That sounds so wrong!)
Can I buy it at any old bike shop or will I have to go halfrauds!?

Might have to be a garage jobbie, I've given up

Tried all the above but not the carb cleaner, was advised that's not the best idea by hedgehog so may have to take her to irelands!

Though might cost a bit at least they should be able to get it back on the road again. It's annoying because it's probably something really simple and I just can't seem to work it out!

Unless anyone wants to earn a few quid

I've seen that sign before...... No where was it!

Yeah, I think I've been through it originally when I had the bike. I'm certain it's a fuel flow related issue. Everything turns spark plugs sparking well, I know this because I got myself a nice jolt too!

I'm sure the carburettor to blame and think maybe some bad fuel or dirt got in when I ran out of juice the other day and had to switch to reserve.

Happy new year all, today I have had the carb off and drained all the petrol out, it looked clean with no water inside the fuel in the bowl, I also checked the jet was squirting and it was freely.

I guess a spray of carb cleaner is next....

Not sure what else to check. Ok off to the garage the do we think??

Drain screw is ruined and I sadly dont know how to get it out.

All holes picked and prodded with wire,and the jets seem secure.

Not sure how to check the timing but I'm sure there's a thread on here. See see what I can find

Thanks again for your help

-- Edited by MikeBarnacle on Friday 1st of January 2016 06:39:56 PM

Again image won't load up from my phone

Will get me one of the screw extractors tomorrow.

Thanks for the help with these, you must have serious patients! Finding this mechanics is really testing my blood pressure, so frustrating!!!! I'm enjoying the tinkering though

Gonna check the timing next......


I'm not sure what the inlet stub is

I don't have the necessary tools to check the clearances at the moment but can pick some up tomorrow

Is there anything else I can check ?

MikeBarnacle wrote:

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I'm not sure what the inlet stub is

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 Mike, this is the inlet stub - it's what the carburettor is bolted to and then the stub is fastened to the cylinder head.

CLICKY

Martyn

Yeah, I have replaced the battery (the other one was duff) I also rechecked with my battery off my XRJ

I'm not sure if it's electrical issue wise, all lights etc work, fuse is fine too,

I haven't check the compression with a proper dial/gauge I just did the finger over the spark plug hole. There was a lot of push.

I did mention earlier about an escape of air. This is coming from the in take snorkel....is this normal?

if you can hear a noise from snorkel could be inlet valve tight or bent do a leak test that will tell you something