Mixing crankcase halves

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This topic contains 3 reacties, has 2 deelnemers, and was last updated by Peter-swe 4 months, 3 weeks geleden.

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    Topic starter
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    One Cdi crankcase with open small half due to oil pump (ciao mix)
    One pionts crankcase with normal, closed small half.
    One gets mazzucchelli 10mm pin crankshaft.
    Reusing the 10mm pin crankshaft with a longer end that drives the oil pump. This one needs the open half to fit.
    Can I swap/exchange the two small halves?
    I want to use the mazzucchelli in the Cdi case
    The only problem I see is a 0.25 mm step at the cylinder. Would it seal?
    Second question: new bearings and seal at the crankshaft, new cylinder group DR43, skirt fits pretty tight in the crankcase but it goes by hand, how easy should it be to spin the shaft without head? Just skinny shaft, no Cdi or flywheel or clutch installed.



    Forum Goeroe
    Berichten: 3525

    It woud seal,  But you have to make up for the difference by using lath copper. Otherwise, the cylinder will skew. Usage liquid gasket in combination whit paper.

    The cylinder shirt must be able to move freely in the crankcase. If you have to press it in, the shirt just springs in a few hundredths and that is at the expense of your piston clearance.

    After assembly, the crankshaft should rotate freely.
    If not,  It helps to heat the crankcase to 100 degrees C and give it a tap with the hammer here and there and the bearings snapped into place.
    The seals give a lot of resistance to turning.
    It is important to grease these during assembly.

    • Deze reactie is gewijzigd 4 months, 3 weeks geleden door zevenenergie.

    Topic starter
    Berichten: 7

    Crankshaft moves good when rotating in the crankcase only (two new bearings and a lubricated seal resisting)
    Force required to get the cylinder skirt in. This is when the cylinder does not move properly when it hits the pots-definitely more resistance-makes absolute sense, what you are saying. I should spilt the case, shaft out and open up the cylinder skirt diameter a bit.
    Thanks for teaching me!
    Hopefully I’ll learn a thing or two on the first two engines.

    Has anyone cut the oil pump driver off the mix crankshaft?


    Topic starter
    Berichten: 7

    Lath copper-copper mesh? Where does one source such thing? Or are you saying liquid gasket and paper might do? What is an acceptable sealant? Hylomar based something? Every forum seem to favor something different…

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