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  1. #1
    CB750 New Member stevecr1's Avatar
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    1980 CB750F Ignition Housing - Oil seeping in

    Hi,

    I have a CB750F that has 3K miles. Restored after sitting for 25 years. Took off the left ignition cover plate to check the timing since running rough. Noticed oil leaking into the housing. Looking at the engine schematics can't tell if there's a seal inside, just the lower crankcase gasket, both, or something else to keep oil out the of ignition housing. Or is some oil suppose to be there for the starter clutch assemble which sits behind the spark advance unit. Minor leak at idle. When increasing the revs, oil sprays out like mist. Pic from Honda manual attached.

    Any help would be appreciated.

    Thanks,

    Steve

    Click image for larger version. 

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    Last edited by stevecr1; 10-24-2017 at 11:45 PM. Reason: Add pic

  2. #2
    CB750 Enthusiast usmc5811's Avatar
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    I get a drip from there if I let it (Ď78 CB750K) idle on the side stand - been wondering about this myself.


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  3. #3
    CB750 Guru amc49's Avatar
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    Oil is in there and normal, the compartment is open to the crankcase. Why like the completely enclosed Dyna ignition system fails so easy, the hot oil kills them.

  4. #4
    CB750 New Member stevecr1's Avatar
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    amc49,

    Thanks for letting me know. I guess the manual should worn you when you're checking the advanced timing by increasing the rpm to 6k. I was not expecting droplets of oil to hit my timing gun and me

    Appreciate your help!

    Steve

  5. #5
    CB750 Enthusiast usmc5811's Avatar
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    Good to know!


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