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

ttboof · Super Guru

Bugger

TerryK · Super Guru

Bugger all right

Terry

ttboof · Super Guru

Back in the shed might see if it sells as is if not rebuild as everything else is 100%

ttboof · Super Guru

Got my brothers bike as an option only has 117ks on it

Will weigh up the options

petenz · Super Guru

she's stuffed mate... your best option is to brake it down

and sell it as parts...

PS.. I will take the head.....

pete

.

-- Edited by petenz on Saturday 15th of September 2018 05:27:34 AM

ttboof · Super Guru

I've found some low k ttr S at good prices might get one and keep this one for parts

Petenz Will keep you in mind if I want to sell the head

TTRfan · Super Guru

Sorry to hear that Les cry

After the bang, it sounds like the engine still ran as you were trying to continue so that kinda rules out any problem on the flywheel side of things.

Did the TTR roll easily so no binding in the gearbox? If you put it in gear does it still roll with no resistance?

I hate mysteries and would love to know what's occurred. Very unusual for a gearbox to give up. Trying to think what might have failed.

Could I persuade you to drop the oil to see what's in there in terms of metal swarf or shards? Also pop the clutch cover off to see if it could be something simple to do with the clutch?

Brian

ttboof · Super Guru

It runs in neutral as soon as its in gear when I let the clutch out it locks up

It was in third gear accelerating and it went bang and locked up to get to a pick up I rode in fourth gear with it missing drive like a tooth missing

Eventually went bang again and only runs in neutral or with the clutch in

Starts and runs well in neutral clutch in then select a gear let the clutch out and it's locked up and stalls

Won't get to look at it for a few days or next weekend

ttboof · Super Guru

You got me thinking Brian

Went to the shed (in the dark)

So neural rolls OK

Can select all the Gears up and down

In gear clutch in rolls with the usual clutch drag however feels and sounds like its missing a tooth and it's the same in all gears

Is there a common gear to all gears output shaft gear maybe

Bikes done around 60000ks maybe more speedo hasn't worked much. Doesn't use oil only ever changed the plug and regular servicing every few rides still all original

Just read your bottom end rebuild thread looks pretty easy

If i can fix it might do the wisco piston and a bit of porting

-- Edited by ttboof on Saturday 15th of September 2018 10:38:56 AM

petenz · Super Guru

ttboof wrote:

Just read your bottom end rebuild thread looks pretty easy
If i can fix it might do the wisco piston and a bit of porting

-- Edited by ttboof on Saturday 15th of September 2018 10:38:56 AM

NO NO NO.... Bad idea....

...

TTRfan · Super Guru

It's worth taking the clutch cover off Les - might be an easy fix!

ttboof · Super Guru

Will have a look in the clutch cover first

Had a look at the gears online if it was in the box I'm thinking it would be limited to only one grear not all of them

Agree the ones pictured will affect all gears

But engine and clutch work OK

Only stalls as clutch takes up

Which makes me think it might be a bit deeper

Now I want to get in and have a look will keep you informed

-- Edited by ttboof on Saturday 15th of September 2018 11:23:29 AM

TTRfan · Super Guru

I am willing you on to take off that clutch cover Les wink

This is a view of the gear and selector mechanism. Steve has the cluster for sale in his shop here

The top set of gears are the driven gears and the clutch assembly attaches to the left of it where you see the threaded end.

The bottom set of gears are the driven gears and the sprocket fits on the threaded position on the left.

Six cogs on each for the 6 gears on the TTR.

I am trying to imagine how it works and can't see that any one cog is constantly engaged but, hey, I have been known to be wrong biggrin biggrin biggrin

Gear cluster.jpg

Brian

PS I got a feeling that this thread might have to be moved to the Repair and Maintenance sub forum in the very near future - hopefully!

ttboof · Super Guru

You've got me thinking Brian got up early and it's covered in truck wash ready to hose down when I get home later today

I can rock it in first gear until I get to a point it rolls and just makes a grinding noise .

I will start digging deeper soon

Not as annoyed as I was yesterday biggrin

ttboof · Super Guru

Dumped oil and Took side cover off no swarf no chunks just spotlessly clean everything looks good

Checked it again before pulling it down only ran with clutch in let it out and it stalls

Rolls when pushed but nasty noises inside

Come this far will pull the motor out

ttboof · Super Guru

Dumped oil and Took side cover off no swarf no chunks just spotlessly clean everything looks good

Checked it again before pulling it down only ran with clutch in let it out and it stalls

Rolls when pushed but nasty noises inside

Even the oil filter is clean

Took a couple of pics

Come this far will pull the motor out

ttboof · Super Guru

Progress

Now to read Brian's info

TTRfan · Super Guru

Really weird Les - no metal bits or swarf in the oil confuse

I am really puzzled as to what might have happened in your gearbox so I am looking forward to your next instalment biggrin

Brian

leigh · Senior Member

Me too - I have the popcorn ready.

ttboof · Super Guru

Keep the popcorn warm

Pulled the top end off after work

Still have hone marks in the bore but oil ring was stuck

Rolling the motor on the bench I heard a rattle tipped it upside down and a few teeth and a but if gear fell out I can see there are teeth missing of the gear closest to the clutch (inside the box)

That's as far as I got tonight

Now for some Shepard's pie

The ttr may ride again

-- Edited by ttboof on Monday 17th of September 2018 11:49:49 AM

ttboof · Super Guru

Tempted to start ordering parts but will wait until I have checked inside for any major damage

TTRfan · Super Guru

New individual gears are expensive Les and I wouldn't be confident about mixing new and old. I am sure you would be able to find a good used gear cluster at a sensible price as an alternative.

Brian

ttboof · Super Guru

TTRfan wrote:
New individual gears are expensive Les and I wouldn't be confident about mixing new and old. I am sure you would be able to find a good used gear cluster at a sensible price as an alternative.
Brian

I've made the decision and bought a full set of gearbox internals from a wrecker online $140.00

All gears shift drum rods ect

Question for Brian as I'm not taking the crank out can I get away with leaving the flywheel and sprag on as the sprag clutch is OK

Will still take cover off and flush

TTRfan · Super Guru

You're a fast mover Les!

I can't think of any reason why you shouldn't leave the flywheel on other than the possibility of swarf or gear teeth parts sticking to the rear of the magnetised flywheel out of sight - but that might be me being over cautious disbelief

Brian

ttboof · Super Guru

Good idea agree I'd better take it off and have a look

The labour part doesn't take long the waiting for the parts to arrive is annoying the gear box parts will be a few days then the top end stuff

With the top end id like to take it out to the max rebore size for a little more capacity

Weighing up the loss of an option to rebore if needed

PS I have trouble leaving jobs unfinished. Drives me nuts but will make sure it's done 100%

-- Edited by ttboof on Monday 17th of September 2018 10:08:16 PM

Benjah · Veteran Member

Popcorn warmed and standing by.

-- Edited by Benjah on Tuesday 18th of September 2018 12:07:25 AM

Kaos · Senior Member

ttboof wrote:
Good idea agree I'd better take it off and have a look
The labour part doesn't take long the waiting for the parts to arrive is annoying the gear box parts will be a few days then the top end stuff
With the top end id like to take it out to the max rebore size for a little more capacity
Weighing up the loss of an option to rebore if needed
PS I have trouble leaving jobs unfinished. Drives me nuts but will make sure it's done 100%

Bore it out!!!
My 2 mm over 263cc is good, but 325 would be better, 350 best.
Watching with interest.

-- Edited by ttboof on Monday 17th of September 2018 10:08:16 PM

ttboof · Super Guru

Thanks kaos I was going to ask if going 2mm os is a good option

Waiting on fly wheel puller so I can fully dissemble and clean bottom end new internals due end of the week

Then the top end rebuild

Anyone got the output and gear lever seal numbers so I can drop into a bearing shop while driving around for work

Been a while since I've gone this deep in a motor is surprising easy

TTRfan · Super Guru

ttboof wrote:
Waiting on flywheel puller so I can fully disassemble and clean bottom end.

If you are in a hurry Les then you can use the rear axle - same thread wink

ttboof · Super Guru

Thanks Brian had the guy at the Yamaha shop say the same thing but happy to wait as the parts will hold me up now

The puller is really cheap I like cheap biggrin

Thanks again for the encouragement and support from you and the forum members enjoying the job so far

TTRfan · Super Guru

ttboof wrote:
Anyone got the output and gear lever seal numbers so I can drop into a bearing shop while driving around for work

Good to see TTR owners getting down and dirty with their steeds! I am sure many think it's a black art and a degree in engineering is needed to get into a TTR engine but a number of owners such as yourself are giving others confidence to have a go - well done biggrin

I got a new gear lever seal here and the size on it is 14x26x6 but I don't have a transmission seal. The one I checked in a crankcase didn't have the size stamped on it. It's worth checking to see if yours does - if you haven't already wink

Brian

PS If you are using my "how to" web page please let me know if I can add or change anything to improve it please!

ttboof · Super Guru

Thanks for the seal size will see if the number on the drive one helps tomorrow

TTRfan · Super Guru

So you need an SD 25x40x6 seal. As I understand it the SD part is important and means it is a radial shaft seal with a primary seal lip and an auxiliary dust lip - you only need to consider this if not buying the genuine OEM seal. See here for more info.

ttboof · Super Guru

I drive about 1000ks a, week across a few offices so have a choice of shops to drop into no luck on the seal so a Yamaha shop 100ks up the road ordered two seals and both gaskets to cheap but to do them . Just finished splitting the cases hot buts of great box out of evrrywhere

Found one bearing is OK but just not happy with it it's the rh end of the output shaft 6203DLA8

Will try a bearing shop or order from Yamaha

Will be 100% once back together then it's the top end

ttboof · Super Guru

If you look close the part the selector goes into snapped I'd say thats copped a hit from the gears dying next to it

petenz · Super Guru

And it had to be the one gear thats part of the output shaft...

and 6th gear to.... think it would have been colataral damage from the

dog braking...

..

-- Edited by petenz on Wednesday 19th of September 2018 11:12:05 AM

ttboof · Super Guru

Yeah I will have a close look at the dog and see if it's been cracked for a while or just broke

Saw one at the shop this morning been used as a commuter with 140000ks on it with the engine never been open that's the most I've seen They recon gears just don't fail in ttrs but mine has biggrin

TerryK · Super Guru

petenz wrote:
And it had to be the one gear thats part of the output shaft...
and 6th gear to.... think it would have been colataral damage from the
dog braking...

When I rode MX I stripped top gear 3 times, being 5th it was the weakest gear & I ended up using different oil & never had another issue, I had to slow the gears down, we did do flat changes without using the clutch.
Terry
..

-- Edited by petenz on Wednesday 19th of September 2018 11:12:05 AM

Kaos · Senior Member

ttboof wrote:
Yeah I will have a close look at the dog and see if it's been cracked for a while or just broke
Saw one at the shop this morning been used as a commuter with 140000ks on it with the engine never been open that's the most I've seen They recon gears just don't fail in ttrs but mine has

"they reckon TTR gears don't fail". They also reckon DRZ400's are bullet proof too, but mine failed and jammed up solid in the gearbox in 09, couldn't even push it. Was a broken selector fork which went through the gearbox caused a bit of carnage.

Anything mechanical can fail. I got a second hand motor off ebay motor and sold the bike off.

I was pissed off for a while at my bad luck, until I realized it wasn't a bummer but an opportunity. Opportunity for an upgrade. Ended up with two Yamaha's!! smile biggrin Oh and a box full of DRZ parts.

ttboof · Super Guru

I've changed the oil several times a year with Castro active 4 mineral motorcycle oil . I think I will change to a semi synthetic bike oil just to be sure

Every thing else looks good except the couple of high load gears

Thanks for the advice

TTRfan · Super Guru

ttboof wrote:
Saw one at the shop this morning been used as a commuter with 140,000ks on it with the engine never been open that's the most I've seen They recon gears just don't fail in ttrs but mine has

I am guessing that was 14,000 kms but, even so, that is 86,992 miles - wow!!!

There always has to be a first and that, unfortunately, is you Les

I can no longer say that I have never known a TTR gearbox to go bad cry

Brian

PS Can't see much wrong with the oil you were using:

APPLICATION

Castrol ACTIV 4T 15W-50 provides good lubrication for all street and off-road four-stroke motorcycles. It is also well suited to a wide range of four-stroke petrol engines used in generators, lawnmowers, and light power equipment.

FEATURES & BENEFITS

Provides a protective film on engine parts in all conditions
Significantly reduces engine wear during start-up and warm-up
Improved engine cleanliness, promoting longer engine life
Excellent wet clutch friction stability even in severe applications
Enhanced gear wear protection for transmission gears

SPECIFICATIONS

Exceeds JASO MA, MA2, API SL

TerryK · Super Guru

ttboof wrote:
I've changed the oil several times a year with Castro active 4 mineral motorcycle oil . I think I will change to a semi synthetic bike oil just to be sure
Every thing else looks good except the couple of high load gears
Thanks for the advice

I wasn't saying the oil caused your failure but as it happens I use a semi syn in all my bikes, BTW the MX bike was a 2T so the oil was for the gearbox only & the flat changes along with not using the clutch caused the failure but by using the oil it slowed the gears & protected them but I bet I lost some power in doing so.

Terry

ttboof · Super Guru

Thanks for the oil info guys I'm happy with the active 4 but a semi synthetic won't hurt trying

All ideas and feed back apreicated I've been working on bikes for ever but like finding new idead/suggestions

No Brian the ttr at port macquarrie has done 140.000 no typo just regular servicing at the bike shop it'd had an easy life sealed road commuting 90ks per day for years

TTRfan · Super Guru

Ah - sorry Les - I got my conversion wrong by a factor of ten coz 140,000km is actually 86,992 miles disbelief But that's gotta be a record eh?

ttboof · Super Guru

TTRfan wrote:
Ah - sorry Les - I got my conversion wrong by a factor of ten coz 140,000km is actually 86,992 miles But that's gotta be a record eh?

I was in the Yamaha shop again today but the high mileage ttr was out was going to take a pic

That's the highest mileage I've seen but as its all highway commuting easy to get that up

I do at least 1000ks a week but in the work car so doesn't count

They

Only had one with 2500 ks for sale looks a bit rough

petenz · Super Guru

got me thinking.... i have blowen 3 gears boxes... broken dog in one... missing teeth in the
other 2..... they were all Yamaha's....
Is it a Yamaha thing.... or is it that I have owned and abused a lot more Yamaha's than other brands...

bikes were... RD400E / YZ125F / IT465H
37 bikes and only 3 gear boxes.....not to bad I surpose...

..

ttboof · Super Guru

Agree I've had a lot of Yamahas as well all things can break but the numbers support gearbox failure is rare . It's surprising the work bikes do without complaint.

Looking forward to having the ttr going again

ttboof · Super Guru

Friday Arvo back from work and new Gear set had arrived so all set to reassemble the bottom end over the weekend

Guy I started my apprenticship with has his own engine business now checked the head still OK but going to service it with new stem seals and the valve springs could go back but recommends new ones lost a bit of boingness (non technical term)

Will stick with Yamaha os piston ect

As the Yamaha parts are surprisingly cheap and should be available

TTRfan · Super Guru

You are making progress Les!

Tip of the day - remind yourself where the thrust washers go and don't forget to fit them - nothing worse than finishing a build just to find one at the bottom of a box - don't ask how I know that disbelief

ttboof · Super Guru

Thanks Brian will have your pics. My pics and workshop manual on hand

Main reason I want to get bottom end back together although simple it's still fresh in my head

I've put cable ties though all nuts washers ect with the aim to help get them back right