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Aircooled Monoshocks

  1. Hi, I am having some issues setting up this air cooled mono, its recently had a full engine rebuild, I have cleaned out all the exhaust system and repacked it, i have had barrel off for inspection and this would appear to be correct, i have stripped the carb down and to be honest its very clean(original 26mm TK), it would run then suddenly stop...this faulted to the ht secondary ...replaced aok, i rode it 3/4 throttle up a long hill and then did a plug chop)nicebrown/tan colour(, the problem is lower down in carburation especially when warmed up, i believe the pilot maybe a tad weak, anyhow iset air screw to 2 out, and rode it around fine tuning on air and tickover then i…

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    • 17 replies
    • 7k views
  2. Started by thai-ty,

    On the verge of locating and (hopefully) purchasing a 2nd plastic tank. Anybody own one of Paul @ Shedworks tank shelters for a ty250 mono? IMO they look great, but... Questions; How easy is it to remove for servicing the air filter? Do you remove the shelter and the tank stays in place each time? Or is the rear tank bolt not fitted and the whole thing pivots up at the front? How strong is it? ie can you sit on it, resting, in between sections? Any other opinions? Thanks in advance.

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    • 4 replies
    • 4.2k views
  3. Started by newnewmember,

    Hi, does anyone know a good jetting starting point(main+pilot) for 26mm PWK f/side carby for a TY250 mono, Ta.

    • 0 replies
    • 1.9k views
  4. Started by murph,

    Hi, I'm considering a 1985 jap import TY 250 Mono, just wondering what peoples thoughts are on these, any pros cons or things tor look out for? This has the autolube fitted, is this system easily removable, being an import are their any specification changes to be aware / wary of? Cheers!

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    • 1 reply
    • 4.4k views
  5. Started by stu109,

    Hi I have a JCM 323 that I use infrequently. At the weekend it started fine on the Saturday afternoon, but at the Sunday trial nothing (although there did appear to be a week spark). I suspected the kill switch and with this disconnected it works fine. The switch was connected to the blue wire on the Motoplat ignition coil and I think it just breaks the connection. Today I have fitted the lanyard type switch from my Beta (and it worked fine there). This still does not work, but again with the blue wires just connected it fires up every time. I have put a meter across the lanyard switch and this seems to show an open circuit with the cap on and …

    • 4 replies
    • 3k views
  6. Started by old trials fanatic,

    In the process of putting a Fantic 305 back together and the discs are knackered. Found someone who will make some for me but they have asked if i want wavy ones or just std discs. Question: Ive seen wavy discs on bikes but never knew why. So why would i / should i fit wavy discs and if i do drilled or not ? Sorry but most of my trials experience has been with drum brakes and i have no idea why you would want to fit wavy discs in fact they look like they would feel really weird in use a bit like having distorted drums but i'm probably dead wrong. So please enlighten me before i spend my hard earned. Thanks

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    • 16 replies
    • 8.9k views
  7. Started by 340bulltaco,

    Hello there, I cut a small piece out of the back of the box for a look-see and it is a real mess of packed solid gunge and carbon. I've seen the very helpful pics from Searay175 on 03/11/16 (attached) but can't quite figure out the best place to cut the rear end of the box. There doesn't seem to be a lot of space to cut between the outlet and the mounting bracket like he did and it looks like that would be a real pain to weld up again. Any words of wisdom would be greatly appreciated.

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    • 6 replies
    • 4.7k views
  8. Started by 340bulltaco,

    Simple, thanks again to thai-ty.

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    • 3 replies
    • 4.1k views
  9. Started by europa,

    I am currently rebuilding a JCM 240 Europa - one of the Streit models - I think 1989. I dont appear to have the correct rear brake set up. does any one have a parts diagram or photo of the correct caliper & cylinder? unit I have is a Brembo but the hose looks short, Cylinder mounting screws are 6mm - holes in frame are 8mm. any of you guys have any experience of this?

    • 1 reply
    • 2.8k views
  10. Started by thai-ty,

    My two 1984 Yamaha ty250 Mono's.

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    • 13 replies
    • 6.8k views
  11. Started by europa,

    I am rebuilding a JCM 240 Europa from the late 80s. when I was replacing the fork seals ( I believe these should be Marzocchi ) I found the internals of the 2 forks are completely different. is this normal & does anyone have a parts diagram or any maintenance info on these forks?

    • 3 replies
    • 2.7k views
  12. Started by steve,

    Can anybody help with jetting for a Mikuni VM26 for use on the Yamaha TY250R? The carb is new and was supplied supposedly set up specifically for this bike but it is way out. It'll barely run past idle it is SO rich, as if the choke is on. Supplied jetting is - Needle 5L8 Needle Jet 182 N8 Main 125 Pilot 35 Slide 2.0 Or at least I think this is right as I can't see the flipping numbers and had to photo them and zoom in as best I could.. Thanks. Steve.

    • 0 replies
    • 2.9k views
  13. Started by motoswm,

    Decided to do an air cooled mono, after spotting a frame, tank and seat for an Armstrong at this years Telford Show. With only 80 ever made, it hasn't been the most straight forward renovation, but its getting close to completion. Everything mechanical has been done and its all running and riding.....however 2 parts have eluded the search. Its missing the airbox and sump shield. I have resigned myself to the fact that both will need to be made from scratch, unless anyone out there has anything they want to sell ? If there was anyone with a complete Armstrong/Can Am mono that would be kind enough to take their bash plate off and draw round it for a pattern, I …

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    • 7 replies
    • 6.6k views
  14. Started by shercosteve,

    Hello, Trying to learn about TY Yamaha's prepped by John Shirt in the mid 80's. I have one that I know has been in the US since 1985, I've noticed a few items that seem to be different than a stocker, Mine has John Shirt stamped in which appears to be a different style silencer than stock. Can any one tell me what John did to these bikes. Thanks, SB

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    • 15 replies
    • 13.5k views
  15. Looking for a bit of info as to what it is really, I thought it was an Amigo 80 Now I've got the bike looking at images online I'm not sure exactly what it is. I have front disc and rear drum, 21 & 18" wheels, its fitted with a Franco Morini engine but the bore size is marked as 39mm which I think makes it a 50. Unsurprisingly it needs a new rear mudguard, I've tried the one from my Skywalker and its a spot on fit, which seems to rule it out being a Alevin as i found a reference saying they were close but not right. I've messaged Harglo to see if they have any engine spares remaining, if not does anybody know anybody else who may have spares o…

  16. Started by slogger,

    Hi all, I have recently had a TY Mono fully rebuilt (engine) but whilst it runs "ok", comparing it to a friends on Sunday who has recently bought one the engine goes appear more flat. Now that I know the engine itself is 100%, I want to explore the front exhaust (the rear has been replaced with a new box) and also the carb, so questions: 1) I have a brand new Mikuni VM26. Has anyone tried one of these and do they have a starting point for jetting (slide, needle etc) 2) Are replacement front exhausts available or is it a "cut it open and weld it up" affair? thanks, any advice appreciated....

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    • 11 replies
    • 7.2k views
  17. Started by hoodie2,

    Been noticing that there are a few after market shocks available for the TY250R. Rock shocks, Hagon and now even an Ohlins unit from CTC. Anyone fitted any of these and come to any conclusions on them? My original shock is okay so I'm not needing a replacement, just wondering about whether the performance is much better and what the weight saving is. Cheers Hoodie.

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    • 3 replies
    • 5k views
  18. Started by paul1989,

    My clutch on my mono has bad it! I'm wondering if anyone knows if the clutch plates are the same from any other yamaha models? I don't fancy paying £58 just for friction plates. Thanks Paul

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    • 3 replies
    • 3k views
  19. Started by brentmain,

    Is there anyone who still produces aftermarket Pink Mudguards (Fenders) for the TY?

  20. Started by gasgas249uk,

    Just before Christmas i got the tip off that Lluis Gallach's Alfer was up for sale. Up to this point it was just one of those factory bikes that had disappeared and i had no idea where it had gone to . Neither had Lluis. So , before it got the chance to disappear once again i went down there to grab some photos and speak to the owner. He turned out to be Felip Gonzalez who built the Alfer and Scorpa bikes with Albert Juvanty. There are some nice old photos in this report on my hobby web. http://www.retrotrials.com/rediscovered---the-factory-alfer-of-lluis-gallach.html

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    • 3 replies
    • 3.9k views

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