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

Fladdem · Senior Member

Project TTaRt up!

Fladdem · Senior Member

Day 2

So, I took my cylinder-head into work today, didn't get a lot done really, got the valves out, cleaned them up a bit and started trying to get some casting marks out the intake port Laughing All pictures were taken with my phone, I'll try again in my lunch break tomorrow for more stuff.

Valves out. I used a 13mm deep socket held squarely over the top of the valve spring, gave it a quick, but gentle tap with a hammer and the collars bounced out and allowed the springs to be removed to get the valves out. I haven't worked out how to put them back in yet without a valve spring compressor.

Check out the exhaust valves at the bottom! Shocked

After a clean up with the wire wheel, looks like new! (nearly)

The valve stem seals were so loose, there was a lot of play and one valve even fell out as soon as the collar was removed. I'll put new seals in tomorrow or try to clean up the head a bit more in my lunch break.

-- Edited by Fladdem on Saturday 10th of January 2015 09:10:54 PM

Fladdem · Senior Member

Day 3

So, I was late this morning, so as a result they took my lunch-break off me to save taking the wages off me. But yesterday, I was polishing the head some more, until about midnight! Laughing Which is why I overslept I reckon.

I pulled the valve stem seals off, again picture quality isn't great due to using my phone, but you'll get the idea.

Old one

New one

Cylinder head last night.

Not brilliant, but not too bad for an idiot with some wire wool and AutoSol... I'm content with that, in fact today, some of the other mechanics were impressed with the finish I'd achieved. If I was more confident with my knowledge of gas-flowing I'd have a go at re-shaping the ports as well.

-- Edited by Fladdem on Saturday 10th of January 2015 09:12:24 PM

Fladdem · Senior Member

Update 4

I finally managed to get a chance to play with my head again.

I just ground the valve seals in today, I was going to do it yesterday lunch break but after being told we did have valve grinding paste, I spent 15 minutes looking for it, then another 45 minutes waiting for Leamoco to turn up with some and lost the whole lunch not doing anything productive.

Today, no time to waste, valves to be seated!

I have done all four, took about an hour and a half, but I just had to sneak some valve grinding in when it quietened down in the afternoon. :lol: The exhaust valves took a lot of effort to get going, I can still feel the grinding action in my shoulders. I will give it another quick go with the fine paste again tomorrow and then try to start putting some valves back in and seated.

Also, I was playing in the garage and spotted this:

Is not good. Try to ignore the directions given by me to my camera-mum. I don't want to split the cases really, but will if I need to.

Wish me luck!

TTRfan · Super Guru

Some sideways movement is OK (amount allowed is in the w/s manual I recall) but no straight up and down which would indicate a worn big end bearing.

I have only come across TTR engines where the big end has gone because they had been run very low or out of oil usually because the piston/rings were so worn the oil was being burnt or blown out. Otherwise the big ends go on for ever!

Fladdem · Senior Member

Well, that's good to hear then, I'll have to have a look in the manual to see what the limits are, but there's nothing up and down and just a tiny clunk from side to side. The oil did drop quite low sometimes, but rarely below minimum, what with all the oil leaks and leaky valves. I'll need to measure it properly at some point.

Fladdem · Senior Member

Update 5

Finally got around to putting the valves back in the head. There was an old valve spring compressor knocking about in the workshop, worked a treat for putting the collets back in! Thumbs Up

It was a bit fiddly pushing the collets in, but the use of a pair of tweezers and a little pick helped line them up correctly.

I then decided I should replace the little copper washer behind the bolt that holds the decompressor blanking plug in place, no kick-start means no need for a decompressor, hence the pkug. I thought I should do it while there and the washer was leaking a bit of oil.

Shouldn't have touched it. Brick Wall

Stripped the thread out as soon as the bolt came out, all the old thread was intertwined on the bolt.

The picture doesn't show it very well, but I was heart-broken. I carefully tried to re-tap the thread at work and I could screw the bolt in but not tighten it down. So I smothered the bolt in Loctite and tightened it as far as it would go and have left it over night with a g-clamp holding it. Laughing I'll leak test it in the morning with some brake cleaner or something thin and see if it works, if not, I'll get the bolt out and try to find a heli-coil to put in there instead. Hopefully it holds and I can bring my head home and begin re-assembly soon. Thumbs Up

Fladdem · Senior Member

I've not updated this in a while, but I am running another build thread over on another forum I'm a member on which has been updated regularly, I think I best transfer some stuff over onto this build thread.

The stripped out de-compressor plug bolt is leak proof with a tonne of Loctite inside. Which is a relief, I may need to come up with a better solution though for the future.

I have installed new rings.

Bust the old ones on the way out, never mind.

I got my shock back from it's refurb, it needed a new shaft making up, it was bent and corroded, new seals needed to be made and it has been re-gassed and a new bump stop fitted, looks like a new unit. Cost a small fortune though. £225

I needed to replace the swing arm bearings as there was a lot of play in them, I began by removing the chain and rear brake gubbins

The swinging arm pivot bolt was very tight, but I keep an old pair of mountain bike handlebars around to act as an extension to the ratchet.

Managed to beat her out, wasn't too bad, the grease nipple helped to keep it lubricated, I think

Chain slider was chewed up a bit

It had chewed through the metal cap on the arm as well. cry

Eventually, I got back onto the engine and had a right old mare with the valve clearances, I think disturbing everything had pushed them all miles out, I eventually resorted to getting new shims instead of trying to figure out which shim came from which valve, I tried my hardest not to mix them up, the buckets were labelled and I'd made a diagram too. disbelief

Fladdem · Senior Member

I just about managed to squeeze in an order with Brian and Trish before the Sussex's went on holiday.

Look at that! biggrin

Finally replaced the indicator lens after 6 months of a series ii Land Rover indicator lens gaffa taped to the stalk.

Old clutch, at first inspection looks like a lot of meat left on the plates, but was actually quite close to the limit when measured and the material is burnt to a crisp.

I left the new clutch soaking over night

I then went mental with wet and dry paper and attacked the clutch cover.

New clutch in, all torqued up to spec. I also adjusted the little actuator arm, so it was lined up correctly with the casting mark.

I gave the swinging arm a quick clean up

Then began to attack the bearings. I expected a bit of a struggle but I think my regular greasing helped a lot here, I spent more time looking for a suitable drift than actually tapping them out.

All the old stuff

I got a new cap for the end as well

I pushed the new bearings in with a 3mm recess as suggested by the manual and the guide on here. Despite reminding myself constantly while battering the old bearings out, I still managed to leave the new chain slider off the arm before putting it back in disbelief

All torqued up and linkage reattached.

I did manage to fit the new chain slider afterwards, but it was a bit of a struggle. Next job is to stick the carb, exhaust, air-box, give the battery a recharge and fill it with oil and see if she'll run!

Baggers · Senior Member

Great post mate, I love this kind of thing... I recently had a problem with a stripped thread in the cylinder head for my decompressor plug retaining bolt.... Eventually I solved it.. The thread actually goes further into the cylinder head than the thread on the bolt, I found a longer bolt and filed down the end to fit in the groove on the plug, but left a few more mm of thread, which caught in the bit that was left in the head..... Then a liberal amount of locktite and job done :)

Fladdem · Senior Member

Thanks a lot. I want to just get her back together now and go riding, but I want to make a reasonable job of it. I should have thought about using a different solution for that instead of just ramming in a bolt smothered in the stuff, but I have done it again. disbelief

Didn't do much today, I had a go at spraying some stuff that was looking a bit worse for wear.

My new exhaust header with freshly painted heat shield, it's quite a good match for the wheels. I doubt it will last long though with the heat

Sprayed the pillion pegs matte black

And the front brake hose clamp

And the side stand

A problem occurred, however, when I went to install the header pipe. I started to tighten the nut down, and somehow, the thread was all stripped out inside the head.

As an experimental cure, I have cleaned the hole out with my tap and die set, smothered the stud in liquid gasket and tightened it down as much as I could risk it. We'll see if it holds tomorrow night when I try to put the exhaust on again.

Fladdem · Senior Member

Not a lot achieved tonight, stuck my back brake back on

I will replace the brake line at some point. I've got nice new braided lines to fit. biggrin

Got the carb back on.

I put the side stand back on, and re-routed some cables and wiring in the correct manner and replaced some snapped bolts.

I did, however, come across my first (of many) unidentifiable thing without a clue as to where it belongs. I'm just praying it is nothing to do with anything inside the engine. I'm hoping it was just knocking about on the garage floor and has accidentally found its way into the box of bits.

hanzo · Senior Member

Not 100% but there is a circlip like that on the clutch arm sits above oil seal hmm

TTRfan · Super Guru

It seems unlikely but there is a circlip that holds the oil pump drive gear in place but I think it's smaller than the one in your pic. Can't think of anywhere else at the mo.

Brian

Fladdem · Senior Member

Thanks guys, I'm trying to figure out whether I removed any circlips and I can't recall doing so, perhaps it was loose enough to fall off? The problem is the fact it was in the engine bits box, which suggests it came from something important. But I didn't touch the oil pump, nor did I remove the clutch arm, do you mean the arm tha sits on the left of the engine that the cable moves or the arm inside the basket?

I think it may be from the old master cylinder from my pit bike, when I replaced that there was a circlip holding the push rod in place, I'm not sure whether this is it or not? Looking at the diagrams in the manual, the circlips you've mentioned appear bigger than this one. It's about as big as my little finger nail.

hanzo · Senior Member

Yes mate i did mean the arm the cable sits in.. I was going to say it looks like one from master cylinder so could of been there all along like you say ...i mentioned clutch as you been working that area .

Fladdem · Senior Member

It must have been a productive evening, I skinned my knuckles. biggrin

Set to work replacing the bearings in the top of the shock with a polyurethane bush.

Battered out the collars.

I drilled a bit out of the eyelet to let me get a pick in to get the circlips out.

Battered out the bearing with a socket.

I needed to spread the mounting tabs apart to fit the slightly wider bush into the frame.

Got it in, was a bit of a squeeze.

I then put the airbox, battery box, and subframe back on. Next job tomorrow, is the silencer, rear wheel and then get the new chain down to the correct length. I'll then take it for MOT and swap the brake lines over to the new braided ones afterwards. I'm weighing up new graphics as well, but not sure? I need to charge the battery up and then check there is oil pressure.

I didn't want to chuck it together quickly, but the girlfriend has never been out on the back of a bike before and said she wanted to before she went back to uni. There's nothing quite like the prospect of a happy girlfriend to bang a bike back together as quick as possible. wink

TTRfan · Super Guru

Excellent show and tell Adam!

Glad the top bearing kit got to you today - gotta keep the gf happy wink

Fladdem · Senior Member

I got her built up today. smile

New chain, I'm trying 14/48 sprockets now, instead of 14/52, I want to see if it's nicer on the road but I don't want to lose out too much on acceleration.

Yes, chain is a bit tight.

Time to fire her up!

https://www.youtube.com/watch?v=X8Gj2504Lv4&feature=youtu.be

The only issue is that after running her up, after about 30 seconds, the header was starting to glow. It seems fine to me, listening to the engine, but I've never noticed the exhaust glowing before now. I wonder if it's the new header, combined with the ported/polished head and I'm not sure if an iridium plug would have an effect? confuse Would the fresh rings cause it to run a bit hot too?

I may richen it up on the needle and see what happens. I might take it for a quick spin around the block tomorrow night and then check the plugs. Any tips on running it in? Last time I was in there I just rode it as I intended to ride it, I just avoided lugging up hills and massive over-revving.

TTRfan · Super Guru

Getting there!!!

"Last time I was in there I just rode it as I intended to ride it, I just avoided lugging up hills and massive over-revving."

Sounds about right although I limit myself to about 40mph or quarter throttle for the first 50-100 miles (depending on whether I have just fitted new rings or a rebore) or so and then just gradually increase the speed and throttle opening.

Brian

Fladdem · Senior Member

Thanks Brian!

I've been thinking, do you know if the shorty headers are thinner walled than standard, if so, it may explain the more noticeable glow. I've decided, I'll nip around the block on it, check the plug, if all appears OK, I'll stop worrying and recheck in 200 miles or so when I check the valve clearances and dump the oil. I'll worry about jetting and stuff then. A 10 minute ride should give me a plug reading, shouldn't it?

Fladdem · Senior Member

ttr250.activeboard.com/t59947723/suggested-carb-fix/

Just had a read through here.

Thanks Brian!

My header is still glowing in the dark, can't see it in the day, it was nice and shiny before but after 2 miles, it has blued near the port and the coating that was on it has been burnt to make it look amber, instead of shiny stainless steel. I read the plug, it suggested slightly lean. The bike doesn't hesitate or bog anywhere and makes as much power as can be expected from that engine, it's no slouch, it just seems to run really hot. I'm one clip away from full richness on the needle. I believe it still has the standard pilot jet and a Mikuni 140 main. I'm about 2 and a half turns out on the mixture screw, I think I need to upsize on the pilot a bit and possibly go to full richness on the needle.

How can I test the accelerator pump is working, could that cause the plug to read lean? Is it just a case of filling the float bowl and then twisting the throttle body?

-- Edited by Fladdem on Saturday 4th of April 2015 01:20:54 PM

TTRfan · Super Guru

Fladdem wrote:
How can I test the accelerator pump is working, could that cause the plug to read lean? Is it just a case of filling the float bowl and then twisting the throttle body?

Yep - that's the way to do it! The jet sprays directly backwards toward the slide so don't expect it to spray upwards wink

TTRfan · Super Guru

Here is a couple of pics of my polished shorty header after a couple of runs. If anything the mixture on the TTR is rich as it start easily without choke.

I don't know what the colour would be called (bronze?) but I like it wink

Header 2.JPG

Cubber · Super Guru

A liberal rub over with Solvol Autosol will restore the polished stainless (chromed) look.

I would leave it though - it shows maturity and use. (AND - saves Solvol)

Martyn

Fladdem · Senior Member

My new shorty header looks like that already. I like the look, but I was just hoping for shine for a bit longer.

Accelerator pump isn't working. The diaphragm isn't being pulled back down again after the throttle is twisted, the path is clear, carb cleaner was being sprayed out into the venturi. I tested it by putting a 19mm socket over the edge of the diaphragm, twisting the throttle and the arm wasn't being pulled back, I think the rubber may have aged and gone stiff, after 20 years of sitting in petrol, I'm not surprised. I put the needle to the richest setting, no popping on the over-run, no bogging from no throttle yanked round to full. Cleaned the plug up and took her for a run around the block again, I will check the plug tomorrow morning, after she's cooled down.

Fladdem · Senior Member

After six days and 300 KM's, the gearbox has gone. She's stuck in fourth. I'll see if there's anything I can do externally, but I'm not going in again. If it is a case of gearbox dismantling, the bike is going. For two years I have put up with constant niggles from a bike that's supposedly one of the most reliable trailies in the world, I must have bought a dud. I have spent far too much money on it already since buying it, this could be the end.

peteBLUEttr · Super Guru

Arghh nooo man, fingers crossed adam

locky · Guru

What a shame after all that work. Hope its an easy fix..

TTRfan · Super Guru

Hi Adam

Sorry to hear of the new problem.

The transmission on the TTR is very robust. The usual cause of a TTR getting stuck in gear is that the post that hold the gear change return spring breaks its housing. Should be a cheap fix. The photo below shows a casing that I have had repaired. I happened to have the innards removed but that isn't necessary for the welding to be done. I could be wrong in diagnosing your problem but it is worth taking the clutch cover off to check before you send the TTR down the road!

Brian

Fladdem · Senior Member

After sleeping on it, I'm not going to throw Vicky away, how can I when she has a name? It's such an ace bike when it works, that I couldn't bring myself to get rid of it.

That seems like it could be the case, as the gear lever is very sloppy, I was just having a play with it this morning and you can get it to change gear if, for example, you want to go down, you have to move the lever to the point where it feels like it's about to select 5th, then you can click it down to third, and going up is the same deal, push it so it feels like 2nd is about to be picked, then you can pull it up into fourth, it goes up the box easier than down.

I've also noticed it's started weeping oil from around the shaft, I'd not noticed it before, but do you know if the seal is replaceable from the outside? I'm sure I've read on here what seal I need and how to do it, but I can't seem to find it now.

I hope it is that, I need to find someone with a TIG welder now.

Wish me luck!

Baggers · Senior Member

I am wishing you luck mate with Sticky(Gear) Vicky !! Hope its a reasonably simple fix like Brian suggests smile

peteBLUEttr · Super Guru

Yeah good luck that man, bring vicky back to life!

Fladdem · Senior Member

Hi again all, I haven't had a chance to look inside the bike yet, I was working on one of my other projects, my '82 GPZ550, to help clear my head a bit and get away from the TTR for a while. But then on the 26th of April I managed to roll my car on the way to a motocross meeting.

I've broke four ribs on the right, punctured my left lung, lacerated my liver, broke my ring finger on my right hand, cracked my skull open, lost 3-4 pints of blood, cracked my pelvis in two places, chipped my right ankle, broke my left heel, broke the bone in my right foot that goes to the little toe, broke the bone in my left leg that goes down the back of shin and allows it to twist. I had cuts and bruises all over and an arterial wound to my left temple. I have had plastic surgery to put my face back together but I can't move the left side of my face anymore and my left eye doesn't close all the way. I also squashed my nuts between my thighs and that was the most painful thing I think. biggrin

So, anyway, I'm sticking to my nice safe bikes now, not rolled one yet!

That post you described, Brian, is it directly underneath the clutch cover? So, if I lay the bike on it's left side and took the cover off, would I be able to see what's going on inside there? If it is that, do you think that the peg can be re-welded with engine in situ? I am hoping it is that, because the lever doesn't spring back to where it's meant to but you can change gear if you go to change up a gear but stop as it is about to click up, you can then make it click down and vice versa to go up the box. I was starting to get issues though with 4th and 5th gear though, I quite often would get a false neutral when changing from 4th to 5th and sometimes from 3rd to 4th. But, my CRM 250 will do it from 6th to 5th, which reminds me, I did a practise enduro day on the 25th of April and snapped the chain which punched a new breather hole in the crankcase, so I need to sort that too, when I get the chance. disbelief

Oldduc · Member

Glad to hear your nuts are OK!

Seriously I'm glad to hear you are alive after that,let alone any thing else. That looks like a terrifyingly nasty rollover. Best of luck through the recuperation, which sounds like it may take awhile. Perhaps some gentle work on the bike would be good therapy. . They say luck favours the good...
Lottery ticket time?

peteBLUEttr · Super Guru

Jeez not another accident, sounds like you got extensive injuries there I hope you make a good recovery.
How did it roll?

Fladdem · Senior Member

peteBLUEttr wrote:
Jeez not another accident, sounds like you got extensive injuries there I hope you make a good recovery.
How did it roll?

It rolled quite well actually, hahaha! biggrin

No, I don't really remember what happened, I just remember I put the brakes on and then it started to slide I tried to catch it, but it went onto the grass on the left of the road, span round the other way and then I slid broadside into a road sign and a little flowerbed and brick wall at the base of it. I think the wall flipped it up and then the road sign directed it back onto the road again the wrong way up. I wanted to get rid of that Micra anyway, she was rotten, I reckon that's what helped me not die, the extra crumple zones!

I seem to be going OK, I cleaned the carbs on my Kwak the other day, because I could get them off the bike while sat down, then go and sit down while cleaning them. The only issue was the stupidly tight clearance, nothing is as easy on that bike as it is on the TTR, only my Honda Cub 70 beats the TTR for ease to work on.

I mean, which clown at Kawasaki designed this?

peteBLUEttr · Super Guru

Being that you are only 20 will aid your recovery , but I recommend you take it easy, you want things to heal correctly! Na the ttr ain't a bad bike to work on is it, its tricky to even get the spark plugs in on my cb1300!

hanzo · Senior Member

Holy f... looks like you was a lucky boy Glad to hear your on the mend and doin stuff .I Had a serious accident 2 and half year ago cut a long story short I nearly lost my leg , spent 18 months off work .Bikes kept me focused and helped with my rehab was determined to ride again .Credit to you for getting on with it and doing stuff you enjoy wish you a speedy recovery .

locky · Guru

Jesus you have been very lucky to get out of that alive. Best wishes for a full recovery. Glad your danglers are ok ....lol

TTRfan · Super Guru

Fladdem wrote:
That post you described, Brian, is it directly underneath the clutch cover? So, if I lay the bike on it's left side and took the cover off, would I be able to see what's going on inside there? If it is that, do you think that the peg can be re-welded with engine in situ? I am hoping it is that, because the lever doesn't spring back to where it's meant to but you can change gear if you go to change up a gear but stop as it is about to click up, you can then make it click down and vice versa to go up the box. I was starting to get issues though with 4th and 5th gear though, I quite often would get a false neutral when changing from 4th to 5th and sometimes from 3rd to 4th. But, my CRM 250 will do it from 6th to 5th, which reminds me, I did a practise enduro day on the 25th of April and snapped the chain which punched a new breather hole in the crankcase, so I need to sort that too, when I get the chance.

Bloody hell Adam - pleased to hear you are still alive after that one

The post is directly underneath the clutch cover so it's easy to check without further dismantling. This is what it looks like "exposed".

Gear spring retaining peg.JPG

But, if there is a problem with it then you will need to remove the clutch and selector mechanism to be able to weld it up. You can see from the photo below that the clutch will stop you doing any work.

I have had one welded up in situ.

If it isn't the post, I don't know what else explains your symptoms confuse

Good luck in all your issues!!!!

Brian

Baggers · Senior Member

Nasty crash Adam, hope you get yourself fit and well soon mate :)

saintken · Veteran Member

Blimey mate, hope you make a full recovery, makes me sound like a girl moaning about my misfortune, get well soon mate!

Fladdem · Senior Member

Thanks everyone, I should be OK soon, I'm mad of rubber me! And thanks again Brian, I'm glad you have pictures of inside to point out the peg, when I feel up to it, I'll try to get some space to have a look inside, I'm glad you can see the post just taking the cover off, makes it easier to check it is that.

Fladdem · Senior Member

I had a look inside the TTR yesterday, turns out it was that post that had snapped.

It's not very clear but that section of casting has snapped off from the post directly under the clutch. So, that needs gluing back on!

TTRfan · Super Guru

I am sorry to hear that my diagnosis proved correct coz that means work!

Forget putting the broken bit back on - just get that side built up with TIG weld.

Brian

jasparach · Senior Member

Had that happen to me as well ( the spring post broken not the car roll, glad to see that you made it
out of it, looks like a bad one) like Brian says weld it up and it will be fine. I made an aluminium block
to hold mine in place the time it happened to mine until i was able to do a permanent fix, it ran like that
for three years with no bother.