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feetupfun

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Everything posted by feetupfun

  1. I've seen people fit XR600 (alloy) kickstart lever to the Yamaha knuckle, but they shorten them a lot to get them about the length of that one in the photo. I bought an alloy Honda lever for this purpose but haven't gotten around to playing with it yet. I've got an MX250B kickstart lever assembly and a DT250 something kickstart lever assembly as emergency spares for my TY250s and they fit all right but are pretty long and the MX one is very heavy and has a bigger diameter knuckle pin. The standard TY250 kickstart lever is quite a short and light thing compared with the other Yamaha dirt bikes of the era that use the same spline. I think the TY lever is so short because the kickstart shaft is at the top of the motor while the others are only halfway up the motor.
  2. Could also be a leaking crank seal on the primary drive side of the crankshaft. The test for this is if the gearbox oil is disappearing.
  3. The popular two strokes all depreciate due to age for about the first 3 years then their value becomes almost entirely dependent on condition. The desirability of particular brands on the second hand market waxes and wanes depending on what is happening with spare parts availability, or the expectations of spare parts availability in the future.
  4. I would reuse that piston and if the ring end gap is still OK, reuse the rings. For the little end bearing, do a visual inspection on the rollers, the pin and inside the conrod hole with a magnifying glass. If it all looks OK, reuse them too. You will find that trials two strokes running modern oils gum up the rings at an alarming rate, especially if there is too much oil in the fuel.
  5. Maybe they are good storage container for bike parts?
  6. Yes the cable may have been damaged, making the return action (throttle being closed by the spring above the slide) sticky. Another common crash damage thing is the twistgrip tube being pushed against the end of the bars, also making the cable return sticky
  7. feetupfun

    348 torque arm

    My 348 is 195 mm centres
  8. feetupfun

    348 torque arm

    There is normally only a tiny clearance between the torque link and the pivot arm
  9. feetupfun

    348 torque arm

    Post up a photo if you want to know what's up
  10. could also be cable damage
  11. You could get the seller to measure. If you can say which design cover you want I can measure some up for reference
  12. Do you mean a Yam-frame Majesty or a Godden?
  13. Set the nuts so: The pressure plate moves out parallel. There is just enough drive to kick start the motor without the clutch slipping. You can set this with the clutch cover off but the plates need to be well lubed. Stainless steel lock wire. Copper wire work hardens. Of course it would go fine for a while without wiring but do you need the stress in your life of wondering if they were going to move?
  14. The 300 motor performance is very user-friendly but the 300 feels bigger than the 240 to ride. 240 and 200 are both very good twinshocks. If your kid is light enough the 125 is great too. 240 is not what I would call snappy
  15. Sounds like a tight time challenge. Good luck. Those mudguards look great. There's a few things that MK 1 MARs benefit from that you didn't mention. The standard ignition wiring comes out the bottom of the casing and typically gets squashed between the bashplate and the motor. There's an easy fix by rerouting it out the front of the engine casing. Only a problem if the bashplate touches things. The fibreglass bashplate will fall apart real fast if it touches things. That carby may annoy you enough to replace it with something different. If the bike is leaned over, it will flood. The rear axle bends very easily. A common fix is to extend the hub to the right with an extra bearing closer to the RH end of the axle. Kits for this were very common back in the day. The axle holes in the brake backing plates are not all on the same centre as the brake linings. Common fix is to enlarge the axle holes. To get it geared low enough for modern sections using a small enough front sprocket you will probably need to machine the sprocket nut to provide chain clearance. If you fit 360mm shocks with that set of sprockets, the chain will need careful attention to its adjustment to avoid sawing into the cross tube under the lower chain run.
  16. The Scorpa 125 fourstroke with the Yamaha engine is a nice bike and incredibly reliable and long lasting. They are fine to ride but were seen as underpowered by many potential customers
  17. Should be only one ball in total, but if there is three then it is probably just a work-around for the pressure plate being too far to the right
  18. Yes not all threaded clutch hub spring studs are the same length and also yours may have had the original studs replaced. Also there is more than one length for spring buckets, but you said it was the studs hitting not the nuts hitting.
  19. I don't think this is what you were describing but maybe it might jog someone's memory
  20. You can buy them from Yamaha shops
  21. Yes I give many ****s about geometry and have a strong interest in the geometry of 1970s trials bikes. They are great fun to experiment with. I make my own drawings because manufacturers specs are way too vague, sometimes wrong and usually refer to an unladen bike. Modern bikes have excellent geometry already and people fine tune it with the suspension, handlebars and footpegs.
  22. I just remembered how much I liked that avatar
  23. Could indicate air ingress and if so, most likely the magneto side crank seal. Could also indicate a sticky throttle cable or slide. In neutral the revs should go straight to idle RPM when the twistgrip is released.
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