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About tony27

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    Advanced Member

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  • Bike
    jarvis rep,ty250c

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  • Location
    Palmerston North New Zealand
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  1. Next item to modify (for me) Rear Brake Lever

    Makes balancing much easier, generally the kits that are sold also move them rearwards a bit
  2. TY250 1974

    When I get in to sorting my C out fully I'll probably order a 28mm from mid atlantic trials as well, I have extensive mods to the airbox & a WES muffler so it definitely fits what they say is required to run the bigger carb. They are certainly well priced & now that new airbox to carb tubes are available stretching to fit the larger carb is not so worrying
  3. TY250 1974

    You have the standard carb, parts aren't as easy to find as they are for the later mikuni carbs EBay is probably your best chance for finding what you need
  4. Advice/thoughts on top end and clutch. 74 TY250A

    No special tools needed to remove the plates, only if you're removing the hub & basket Probably nothing wrong with the friction plates, have the feeling the only steel in the clutch is the drive plates & that the friction plates are plastic but I could be wrong. If you do strip the clutch either deglaze the steel plates with wet & dry sandpaper or get them blasted
  5. clutch sticking

    Same fibre plates as used in Betas What condition are the fingers on the clutch basket in? If there are any notches from the plates I'd order a new 1 along with rivets & rubber dampers off Splatshop, actually quite cheap & there is a page on their site showing how to do it. When I did mine I also upgraded to the later hub which flows oil better but it wasn't really needed, motor was much quieter after doing that as well
  6. Struggle to start Sherco when it is warm

    I bought a new lever for the rear tank models & it definitely makes starting the bike easier, doesn't sit in against the muffler properly but not by enough to foul your leg. It is slightly longer which does give more leverage
  7. Aargh, '04 2.5 fork spring spacer jammed in rebuild

    Replace the bushes, when worn they put more pressure on the seals by allowing oil past. With good bushes in the forks the seals should last for years, make sure you release the air pressure that builds up during riding at the end of the day to help prolong the life of the seals
  8. Show Us Your Ty

    I had a 350, lots of chrome missing from around the exhaust port mainly so it rattled a fair amount but still ran well. Felt like being halfway up a ladder until I lowered the pegs, did my own disc brake conversion for the front wheel. Disappeared from sight after I sold it to upgrade to a 95 Gas Gas JT350, as far as I know it hasn't reappeared in the last 20 years
  9. Oil Pump And Light

    Shouldn't make much difference, 1 size bigger if anything but I would be surprised if the standard jetting wasn't a little rich
  10. Sherco 290 06 - No spark

    That's the gearbox mainshaft bearing, no seal needed there. Crankseal is behind the gear that the clutch case is covering on the right, water needs draining to remove the casing & if you pull the waterpump cover with the hose still connected it helps with getting the waterpump gear meshed correctly when reassembling. Probably a good idea to do the waterpump seals while the case is off & check the condition of the shaft at the same time
  11. Sherco 290 06 - No spark

    Something strange with your cases from the sound of it, should have the sealed main bearings by now like you describe & a viton crankseal between the bearing & primary drive gear
  12. TY 250A new upper end con rod bearing new p/n?

    According to TY Trials the bearing is the same for all twinshock 250s, their wossner kit includes the bearing so it may be possible that when you get your kit there will be 1 included Not hard to get the dimensions of the bearing to cross reference sizes, measure inside of conrod, outside of pin & width of the bearing cage. Partzilla is normally good for seeing what other Yamahas use the same part, would be surprised if it's not a common part
  13. New piston and rings - sources and opinions?

    Are the marks on the bore able to be felt with a fingernail? If they can be then you will probably need to go to the next size piston. Any of the quality aftermarket piston kits will be .5mm larger for each oversize where Yamaha had steps of .25mm From memory & looking at listings on eBay the 311 pistons are made by Izumi, the 438 were made by ART which are cast into the inside of the skirt. If you can stay with standard bore then here is the piston you want, the same seller has rings as well but it looks like it will end up costing more than either a Wiseco or Wossner kit cost - the kits from both are actually for early YZs so you should be able to get both makes fairly easily https://www.ebay.com/itm/YAMAHA-RT2-DT2-RT3-DT3-TY250-STANDARD-PISTON-96MM-OEM-NOS-438-11631-01-96/263601323881?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D52885%26meid%3Da91bf7daaf9446aaa81b98d5252b7047%26pid%3D100005%26rk%3D1%26rkt%3D2%26sd%3D201687499348%26itm%3D263601323881&_trksid=p2047675.c100005.m1851 Here is a listing for the Wossner kit, you should be able to read the part number off the box & ask your local dealer to see if they can source you 1 https://www.ebay.com/itm/NEW-WOSSNER-PISTON-KIT-1974-1979-YAMAHA-YZ250-IT250-TY250-MC250-DT250-69-64-mm/192451397914?hash=item2cceff491a%3Ag%3AX4UAAOSw9vlaexpX&_sacat=0&_nkw=ty250+piston&LH_ItemCondition=3&_from=R40&rt=nc
  14. Any life left in this gas tank? rust repair question...

    Seeing those photos of the inside I definitely wouldn't buy that tank, if that is the state of the tunnel at it's highest point then the base will be a lot worse
  15. New piston and rings - sources and opinions?

    TY Trials sell Wossner piston kits, not specifically made for the TY but if they're selling them you will be safe to use them. The price is good as well, think my 70.25mm genuine Yamaha kit cost me more than that from a seller in France on eBay https://www.tytrials.co.uk/trailandtrialsuk/prod_2768676-812-Full-Piston-Kit-TY250-Twinshock.html The 311 pistons are missing the taper on the skirt where the transfer ports are, the piston hits the crank without the taper & prevents the crank getting a full rotation. Piston is also heavier due to thicker skirt, all other dimensions are the same This is a photo I took back when I bought a 311 piston kit showing the differences from the underside, 311 piston on the left, 438 piston from my TY on the right. I have a couple more photos but this shows the differences best