1966 Ducati Monza 250 Project “No Clue”

Discussion in 'Old's Cool' started by folknride, Dec 25, 2017.

  1. mikeysduck

    mikeysduck Slow Ride to Nowhere

    Joined:
    Jan 18, 2008
    Oddometer:
    460
    Location:
    Acton Ca.
    Re: worn out Amal's. An old school Norton trick was to bore out the throttle body and sleeve it with a stainless liner. Add a matching Mikuni slide and needle. Where do you get the machine work done, or find the correct slide, needle? No idea.
    #21
  2. folknride

    folknride Old Adventurer

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    1,185
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    That Amal that’s on it looks pretty rough, and there’s no choke circuit so the cable is taped to the clutch cable - not exactly concourse quality.
    I just got on motoscrubs yesterday. Did a search but didn’t find that topic. Thanks for the link. Also tried bevel heaven.
    And of course there’s only so much I should buy without the bike in hand.
    One inmate suggested I crack the cases and clean out any sludge before running it, to protect main bearings. Sounds like a good idea, but is there any other way to clean out a motor after sitting for 30 years? Fill with varsol and drain several times?


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    #22
  3. norton73

    norton73 drinkin'

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    I wouldn't use varsol, you don't want clean bearings that oil may not adhere to on your first start up. I have flushed motors with cheap oil, especially if I have managed to sink the bike in a creek or otherwise contaminated the oil.
    Pour it in, in your case, kick it over with out the plug, drain and repeat as you deem necessary. Doesn't even have to be the correct oil for the bike, just any old oil will do. Then put in your choice of good stuff.


    Also, varsol in your oil pump would be bad, you might lose your prime and have no oil pressure on start up, and you would be pumping varsol when you need oil
    #23
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  4. norton73

    norton73 drinkin'

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    Very few people are resleeving Amals any more. I think AMR in AZ is about the last place. These days Amal is making new carbs and the price is not too much more than resleeving.
    I'd go with a mikuni unless originality was important.
    #24
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  5. folknride

    folknride Old Adventurer

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    And I’ve read that the oil pump is a know weak spot on these bikes. True?


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    #25
  6. MotoChuck250

    MotoChuck250 Not older than dirt

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    The oil pump is a bit week. If the engine is reving at a minimum of about 3500 rpm the engine is healthy and happy. It is getting enough oil. If you run the engine under load below 3500 rpm for extended periods of time, the engine will start to suffer from lack of oil. This mostly affects the big end of the crank and you can find a lot of old engines where the bottom end is gone from this problem.

    I have never heard that idling will cause problems on these engines but you don't want to "lug" the narrow case motors.
    #26
  7. MotoChuck250

    MotoChuck250 Not older than dirt

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    Splitting the cases on these bikes is a procedure that requires quite a lot of care. The location of each shim in the cases is very important. You probably want to recheck the end play on the crank afterwards if you are going to work on the crank. You may be required to reshim the crank upon reassembly.

    I am not saying don't split the cases, but if you do then be ready to make sure that you get them back together with the appropriate tolerances.
    #27