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Project FZR fix up

Discussion in 'Your 250cc Projects' started by Yetiburger, Oct 7, 2017.

Page 26 of 26
  1. Linkin

    Linkin The Mechanic - Moderator Staff Member Premium Member Contributing Member Dirty Wheel Club

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    There are a couple of ways to determine stretch

    The manual will tell you to measure the length of 20 pins in the chain and give a spec.

    Another way in-situ with an assembled engine is to check how loose the chain is between the two cam sprockets, it should be very tight and have minimal movement over the whole range of rotation. With a bad chain you'll find spots where it's loose.

    With the engine disassembled and chain removed, you can flex the chain side to side, it should be fairly rigid. If it has lots of side flex then it's worn out.

    You can also bunch up the links and see if they catch or bind, another tell of a worn out chain.

    If you're rebuilding the engine just replace the chain with an endless one so you don't have to mess around with joining links etc.

    Worth noting that with one-way ratchet type tensioners, the chains are worn out long before the tensioner ever reaches max extension.
     
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    Linkin, Jun 8, 2025
    #501
  2. Yetiburger

    Yetiburger Well-Known Member

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    Well, getting the second motor took a lot less time.

    20250615_152116.jpg 20250615_154422.jpg
     
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    Yetiburger, Jun 16, 2025
    #502
  3. Yetiburger

    Yetiburger Well-Known Member

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    Ok guys, how bad are the aftermarket head gaskets? I seem to be struggling to find new OEM ones.
     
    Yetiburger, Jul 3, 2025
    #503
  4. Murdo

    Murdo The Good Doctor Premium Member Contributing Member

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    My Bike:
    1937 Royal Enfield 250, CF Moto 250 V5, Honda's XL250, CBR250, FT500 plus a few others.
    Ive never had a problem with the Chinese Aliexress ones, but I do give them a coat of copper spray before fitting.
     
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    Murdo, Jul 4, 2025
    #504
  5. Linkin

    Linkin The Mechanic - Moderator Staff Member Premium Member Contributing Member Dirty Wheel Club

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    The only time I tried an aliexpress head gasket it was slightly too small to fit over the head studs, so used a genuine one.
     
    Linkin, Jul 4, 2025
    #505
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