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  1. #1
    CB750 New Member gtc211's Avatar
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    Sep 2017
    Location
    Belcourt, ND
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    2

    removing the exhaust cam when crank won't turn

    Hi all. I have an 81 cb 750k with 7800 mi that sat in a garage for 30 something years. The engine is out and on a HF engine stand. I can't turn the crank, even after letting penetrating fluid, the oil sit in the cylinders for several months. The carb bank was off and there were no spark plugs in any of the cylinders. There was water in each cylinder which I siphoned before adding the penetrant and oil.

    I removed the oil pan, no metal, just black sludge. Oil screen was really clean, just a few non metallic particles. So, I was able to remove the intake cam but I cannot get the chain from the exhaust cam to the crank loose enough to remove that cam. I did get both cam sprocket bolts out. Just can't seem to release enough tension to loosen the cam chain.

    Any help would be greatly appreciated!

    Glen

  2. #2
    CB750 Addict Chris in Dorset England's Avatar
    Join Date
    Mar 2017
    Location
    Weymouth, Dorset, UK,
    Posts
    150
    Tap it off with a brass drift. It sounds like the pistons are seized to the bores. You will have lots of fun with that engine, not!

  3. #3
    CB750 Addict Wez_'s Avatar
    Join Date
    Apr 2017
    Location
    Enfield, CT
    Posts
    285
    have you loosened the lower rear tensioning nut and pulled the slack out of the chain. Also, without being at TDC with both #1 cam lobes pointing towards the spark plugs, you really don't know what valve event the valve train is under. Hopefully the valves are not touching jamming the valve train. You can also try loosening the two cam sprocket bolts and tap the sprocket with the chain attached to it off the camshaft boss. Hopefully you don't have valve interference and just rusty cylinders with a chance at cleaning them up. Good luck....

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