Discussion in 'Mini Racing' started by britx303, Jun 20, 2019.

  1. britx303

    britx303 Plagued with FZRs...........

    Might be picking up a ysr50 for my daughter soon. If the engine is too far gone,are there other older yamaha engines that share the same mounting bolt pattern? Anybody here race them or have spares around............just in case we do get it?
  2. Photo

    Photo Well-Known Member

    I had a honda cr80 engine in the ysr I owned. To be honest with you I cant remember if it was a direct bolt on. Have you checked out www.ysr50.com
  3. pscook

    pscook Well-Known Member

    I had a YSR with an early water cooled YZ80 engine. Simple brackets and stupid power. Only rode it a couple hundred yards (store and flip), but the distance I rode it gave me an indication of the potential. I think that XR100s are wedged in with regularity.
  4. pscook

    pscook Well-Known Member

  5. britx303

    britx303 Plagued with FZRs...........

    I went on that site a couple years ago when we first started concidering one for her.......honestly I forgot all about it.Thanks
  6. britx303

    britx303 Plagued with FZRs...........

    I don't want more power yet. I want her to keep learning to make a slow bike go fast first.We do have an rt100 already and looking at YSR engine pics,they look almost the same if need be and yank the engine. The YSR is one of my cousins that has had it since '89 or '90,and he's finally ready to let it go,and he's barely put any time on it. Im sure the engine seals are shot at the very least. I will say a YZ80 does sound fun if it was for me:D
  7. Shenanigans

    Shenanigans in Mr.Rogers neighborhood

  8. fastfreddie

    fastfreddie Midnight Oil Garage

    There's really nothing much complicated about these engines. Dry seal, wet seal, a gasket on each end of the cylinder and you're done.

    People have stuffed all manner of engines into these frames. While you may find a few that are drop-in capable, an exhaust system is still an issue.

    teamcalamari.com is a good resource.
  9. d_alexand

    d_alexand Well-Known Member

    The Yamaha rx50 engine is the same as the ysr50. The dt50 engine uses some of the same parts, so it may be the same too but not 100% positive. I've had a few ysr50's and they're easy to work on, so just rebuild it. I briefly had one with a liquid cooled yz80 conversion, it was fast, but the vibration was horrible.

    Anyways, I still have an oil pump block off plate and maybe one or two other random items if you need them(free). If you buy it send me a pm.
  10. YamRZ350

    YamRZ350 Nicorette Dependent

    1980 YZ 50 is a direct swap I believe. As a bonus, you get GP shift as well.
  11. G 97

    G 97 What's my name

    GSXR 50 For the win.
    Shenanigans likes this.
  12. zrx12man

    zrx12man Captain Amazing

    I raced a YSR/XR100 hybrid for years. IMO, more power does not make a YSR faster, good suspension does. Make sure you have both fork springs (the stock bike only comes with one) and a proper shock freshly rebuilt and sprung properly. The stock motors are dead simple if you have basic mechanical ability.

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