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The TTR250 FAQ web pages -> TTR250 -> Just joined the forum? -> New owner of a 1993 TTR250 Open Enduro - pity it doesn't work!
Post Info TOPIC: New owner of a 1993 TTR250 Open Enduro - pity it doesn't work!
Bananaman


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New owner of a 1993 TTR250 Open Enduro - pity it doesn't work!
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photo (12).jpg

Dear TTR owners - Let me introduce myself? I am an old git of 54 with a passion for motorcycling. My friends think I am eccentric, I have no idea why. For years I have ridden trail bikes, although I am told that I am useless and should stick to road sports bikes. The first trail bike was a standard BSA 650 Thunderbolt which I built up with trail bars, high level exhaust and knobblies. It was interesting! From here I went to an XR250R which I owned for 7 years. I mounted a pillow on the seat for comfort and rode in willies - Moto X boots always seem to let in the water). I tried on several occasions to get it up the 'Widowmaker' at Tommy's Farm in Wales, but no matter what I did it would stop between half way and two-thirds of the way up, back-flip and I would roll back down again. I then bought a WR450 just before being diagnosed with arthiritis - evidently squash three times per week for 30 years isn't good for you after all! The first time out, the gearbox broke and I had to rebuild it. The second time I discovered I couldn't ride it, it made my legs hurt. I didn't need to sell it, several men broke into my shed and carried it away to a transit van and I never saw it again.

After several months, I have come to the conclusion that a nice light 250 with electric start that works and a low and comfy seat would be the bees knees! 8 days ago, I therefore bought a 1993 TTR250 open endure. I am new therefore to this strange oriental machine! It has so far cost me 30 hours of work to try and get it to run properly! For the 8 or so miles when it did run reasonably, vit seemed to handle and steer well and the brakes seem reasonable. If I could get it to go, I think I might like it. Can anybody help?

The symptoms:

The bike started easily and ran well on the bike stand. If I took it out, within 50 to 100 yards, it would cut on all but up to 1/8th to 1/4 throttle. If I then stopped and opened the throttle fully, it would run at about 1,500rpm and felt very rich.

The checks I have made:

1. Stripped and cleaned carburettor

2. Checked all jets were not blocked

3. Checked fuel supply to the carb

4. Checked the float valve works

5. Checked the fuel level in the float bowl with a clear'U' shaped tube

6. Checked the accelerator pump

7. Unkinked the fuel pipe

8. Checked the air-filter

9. Removed the air-filter

10. Checked the inlet manifold rubber (evidently there are poor designers in Japan too - despite Kaizen and Toyota Production Systems)!

11. Checked the spark plug - very black

12. Changed the spark plug checked spark would jump 4mm crisply and regularly

13. Changed the plug-cap

14. Checked the low-tension connectors / terminals

15. Shut off the fuel whilst riding - it went marginally better just before running out of fuel

16. Put choke on whilst riding - engine cut out

17. Checked tank breather

18. Ran without fuel cap

19. Changed the fuel

20. Bypassed the in-line fuel filter

21. Re-set the pilot screw to standard (1 1/2 turns)

22. Tried air screw at 2 1/2 turns

23. Checked compression - ok

24. Kicked bike - made me feel better

25. Checked jet sizes were all correct

26. Fitted a 130 main jet - IMPROVEMENT AT LAST!

27. Dropped needle to leanest position / fitted a 210 main jet - BIKE RAN ALMOST PROPERLY BUT POWER WAS DIASAPPOINTING. Sluggish at maximum revs

27. Upped main jet to 120 - Power still disappointing. Sluggish at maximum revs

28. Bike went for about 8 miles and then lost tickover and kept cutting out if the revs were not kept right up

29. Did a plug chop - plug read lean

29. Stripped and checked carb - nothing dirty or wrong

30. Found suspicious cracks in float - araldited it up

31. Replaced standard jets - Engine will not rev - appears very rich

31. Leaned off main jet and dropped needle again - still rich and hardly runs (8 strokes)

32. Went back to basics - fitted an AMAL MK1 concentric which is a correctly jetted 4-stroke carb - still no change

33. Played with inlet rubber - hardly leaks now

34. Removed air-filter and put hand nearly over air intake - strangely it revved up?

35. Gave up and went in for tea!

I am afraid that I like motor cycles but they don't like me! DOES ANYBODY HAVE ANY IDEAS PLEASE BEFORE I INVEST IN A 9" ANGLE GRINDER?

Nice in anticipation to make your acquaintance! Hope to re-join the 'Green Lane Crew' and do the Hertfordshire, Silverstone and Wantage lanes.........

Cheers,

Chris

 



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Cubber


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Welcome to the weird world of Yamaha TTR250s, Chris.

That is the first time I've seen a Concentric fitted to a TTR, but then, there's a first time for everything, or so I'm told.

I have read through your statement of facts once. Please bear with me as I re-read it a few more times.

It's said that God loves a trier - you must be well up in his eyes by now. 

In the meantime you could do worse than click on THIS and read the detailed and illustrated process of carburettor fettling.

In all honesty, I doubt if the Amal will work well on the TTR. Let's face it - they didn't work all that well on British bikes!

As Arny said, "I'll be back!" - or at least someone else will be.

Martyn

 



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East Budleigh. Devon
texasT


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Welcome Bananaman!

Seems like you have been one busy "git". 54 ain't old, just well seasoned.

With your list of problems and solutions, I am not to sure where to start.

Sounds to me to be fuel related, but since you no longer have OE carb on, you may have lost me. confuse

#33 states that you have "Played with inlet rubber - hardly leaks now "

I am thinking that if it leaks at all it may have something to do with it running bad.

Might start again with exactly what issues you have now, so someone smarter than me (and this site is FULL of them) can be of some help.

But whatever you do, don't give up, Help is sure to come!

greg



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Bananaman


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Thanks - the carb fettling document is really useful! I still can't work it out though. I seem to have tried everything carburation - even changing the carb hasn't helped. I was amazed that the engine went considerately better when I put my hand over the inlet - after all, it was running really rich at the time!  Cheers, Chris

 



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Bananaman


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Thanks Greg,

Still confused as you can see from above! I agree that concentrics are old fashioned and the aluminium slide used to wear quickly. Also the needle had to be changed for a neoprene tipped one and the float valve changed for a 1/8" dia. item, but they did work - I won many races using concentrics on the mainland and achieved a record on the IOM using concentrics, but as you say, they are crap by Japanese standards. As for the air leak - it is miniscule, but I can't seem to cure it. Even if I use silicon inside the rubber it doesn't work - the rubber just slips off the stupidly shaped stub!

No - definitely needs the angle grinder - or maybe an oxy-acetylene cutting torch would be more efficient?

Cheers,

Chris



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Yuraku


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Chris - you've tried everything as far as I can tell from your detailed posting above.

Have you read the carburettor information in the FAQ section? confuse

If not then CLICK THIS.

I'm sure you will find the solution, it just depends WHEN? hmm

Yuraku



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Bananaman


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Yuraku,

Yes, I had read the passage however it obviously hadn't fully sunk in! I read again with interest the carb-stub bit where the rubber moulding comes adrift from the alloy stub. I criticised the design because I thought they came as two parts and not as a bonded assembly. I had clamped plates on each end of my inlet stub, rigged up a nylon tube to pressurise it and immersed the assembly in water. I reduced the leak to almost nothing - but I was still not happy about it. When I asked for a quotation for a new rubber, I was shocked at the price. It is not so bad when one considers that it is the complete assembly that I would be buying. I think I shall buy one - it may or may not be the problem but it would at least give me peace of mind! It is raining here in England and I am desperate to try out my new toy.

Thank you for replying to my blog - at least I think it is a 'blog' - I am too old to really understand what a blog is!

Cheers,

Chris



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Bananaman


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All,

I thought you might like to see an email which I received from a friend today. He is the reason why I said I was useless at trail riding. I have seen him wheelie for half a mile along a twisty shale mountain track in Wales. Makes me feel sooooooooooooooo humble! The Youtube link is worth checking out!

Chris

See – they DO like me!


From: Chris VA [mailto:chris@vass-uk.com]
Sent: 27 June 2013 09:56
To: 'Russell Laird-Morton'; chris.hayden@tiscali.co.uk; adrianmknight@btinternet.com; G.Gibbins@btinternet.com
Cc: roybeatwell958@gmail.com; glennandnicola@googlemail.com; mark.hemmings@apexlinvar.co.uk; len@historicracing.org.uk
Subject: RE: Recalcitrant heap of dung!

Hi Chris

Please can you just buy a new Enduro bike and just get out riding again!! Oh yes, we also need some new footage of you (Banana Man) in action, lol.

See 2005 footage in Wales on youtube:-
http://www.youtube.com/watch?v=AMVNnh-UMKk

Cheers
KTM-Chris

From: Russell Laird-Morton [mailto:rlairdmorton@moog.com]
Sent: 26 June 2013 21:01
To: 'chris.hayden@tiscali.co.uk'; 'adrianmknight@btinternet.com'; 'G.Gibbins@btinternet.com'
Cc: 'roybeatwell958@gmail.com'; 'glennandnicola@googlemail.com'; 'mark.hemmings@apexlinvar.co.uk'; 'chris@vass-uk.com'; 'len@historicracing.org.uk'
Subject: Re: Recalcitrant heap of dung!

Have you tried lubricating the flip rotating gimbal inside the romulating oscillator? Me thinks perhaps not!!!!! Bloody amateurs!

If you cant get it to work you could always shoe horn my plane engine into it?

Just one other idea, take it to your local dealer. They are the real professionals

Good luck!
Sent from my Blackberry.


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brindabella


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I think maybe the energy polarizing crystal insert is defective.
This fitment is required to achieve correct atomization of the fuel-air mix.
It is not listed in the parts manual because they don't want to admit that the bike runs assisted by "magic".
You may, however be able to find a new one on ebay.
The crystal works using quantum action at a distance, however it is usually installed near the carb (depends on model year).
You will probably need a left handed gelatherscrew to remove and replace this critical item.
Good luck.


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Bananaman


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Dear Cinderella,

Are you being deliberately obtuse? I have changed the flux-generator and if you go back to basics, you will realise that the polarising crystal insert is a fundamental component within this device. It enhances lialectic thrust and acts as a catalyst to the derivation of vibratory distribution. The Amal TT carburettor actually had three of these devices wired in parallel to keep the electro-motive power generation stable.

I am at my wits end. Why do I get no useful advice and yet end up having to educate the unknowing in the ways of simple electro-metamorphosis? Am I surrounded by fools?

Yours sincerely,

Chris

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Bananaman


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Hi Guys (& Girls),

I have to be careful saying that nowadays.............. Well, I have now spent probably 50 hours working on the recalcitrant heap of dung! Finally, it is sorted. It purrs like a kitten and it is a pleasure to ride.

I tried a new inlet stub to no avail although it needed one anyway. What I thought was poor design was because it had come apart and had been strapped up with a second hose-clip.

I then thought 'this is it' - and delved inside the engine. I found that one of the valves was tight and that the inlet camshaft was three teeth out! It was not surprising that it didn't run very well. The carburettor was both sucking and blowing, so in effect the mixture received two dollops of fuel instead of one - hence the rich mixture. It explained why leaning off 30 on the main jet and choosing the leanest needle position had made it run a little better.

Sadly, the new set-up lasted a mere 5 miles - 2 miles of running in and three at 75mph! It then expired again. I finally got it going and limped home. The problem? Well, I have two theories - I know which one I prefer!

1. After re-checking the valve clearances, valve timing and plug, I changed the plug to a hotter 'latino' type plug. The different heat range did the trick.

2. All my friends told me that I had bought a 'Girly bike'. I decided that drastic problems require drastic solutions! Having therefore fitted my 'Girly plug', I then put on one of my wife's summer dresses to try the bike out. It went beautifully! So there you go. I remember the same thing with voltage regulators in the old days. You had to re-sex them by changing the polarity from positive to negative earth on different cars.

So - what now? Am I riding it? You must be joking! Trail bikes are fun for the winter, for wet days in sloppy mud. No - it is gorgeous weather and I am just off out on the GSXR1000...................

Thanks for the advice and see you later. It doesn't take much to make an old man happy!

Chris

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Cubber


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Well, I suppose it's a result, of sorts. confuse

I don't blame you for choosing the GSXR this afternoon, I'm electing to go out on Sunday on my old BSA racer. biggrin

BSA%2520L26.jpg

The sun is going to shine I hope - all crossed.

Martyn



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East Budleigh. Devon
Bananaman


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Martyn,

The sun will shine on Sunday because I shall be going out with a friend, he on his Maxtonised R1 and me on the GSXR. It's sort of a cross between motorcycling and racing really. It starts off slow and kind of gathers momentum....................

I do like your bike - I would love a picnic hamper on the GSXR! I imagine it is a C10 or something like that? I loved the Thunderbolt in its day, however it was a real shock to get back on one and to realise that the old memories lied to you and they really were sh1t after all is said and done! Still fun though! When I green-laned the Thunderbolt it actually spat the knobbles off the back tyre!

Now then - enjoy your fuddy-duddy riding! I am sure you will, you will have an excuse to just tootle around and look at the beautiful Cornish scenery! (Please don't tell me it is Devon?)

Chris

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Chris - prior to getting my Cub I converted a 1960ish T110 into a Green Laner. 

It went like stink but was VERY heavy.

This is a typical shot of it on Whitfield Moor - in Co. Durham........

1998%2520Colonial%2520bog.jpg

Would you believe that I sold that thing and got a Tiger Cub instead? Much more manageable.

Thunderbolts are too new and modern for me. no

BTW, it's not a picnic hamper on the BSA, it's a fledgeling mobile phone hamper. (Called carrier pigeons) biggrinbiggrinbiggrin

Here's to Sunny Sunday.

Martyn



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East Budleigh. Devon
Bananaman


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Martyn,

That looks a lovely bike! It would have been very similar to the Thunderbolt. I have never understood why they are so unfashionable. They are miles better than the oil-tanked A65's! They were a pleasure to ride with far less vibration! Mine was however difficult to sell and didn't go for a lot. I finally sold it back to the friend who sold it to me as a non-runner in 1979! I found him on 'Friends Re-united' and renewed our friendship!

Trouble with your Triumph is that it was too shiny! I wouldn't risk that. I fitted a K4 tank which I considered to be 'sacrificial'!

Chris



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scratcher


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bannanaman.. am brand new here too, us aul gits could start a club.. am 54 as well, but am fae Scotland so am hardier...

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