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  1. #1
    CB750 Member Longer's Avatar
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    What should I replace at 85xxxkm

    Bought a CB at 85xxxkm - everything was caked in oil, a few questionable Ďrepairsí here and there. Iím going to assume that this bike hasnít been maintained very well, but has been ridden and kept out of the weather for the most part. My goal is to chop and bob with a next to new engine and carbs fully rebuilt and painted etc. What should I replace as far as the engine and main Ďgutsí go?

    Iím along the lines of replacing every part I can. But unsure if I would need to replace every sprocket, valve, and component of the engine? Willing to spend about $1000 on the engine in parts.

    Thanks for your time

  2. #2
    CB750 Guru amc49's Avatar
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    At that mileage they are pretty used up..........not many of them ever make it that far. You're in a colder temp so that helps.

    Here in Texas the valve seals are cooked at 25k MILES and all of the rubber tensioner parts at 35-40. Rings maybe 50+. The valves all will be dead or not depending on how often they were set correctly.
    Last edited by amc49; 02-13-2018 at 01:21 AM.

  3. #3
    CB750 Member Longer's Avatar
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    So we’re talking a full overhaul then.

    They were probably not set at all. It didn’t run too well when I drove it home from the previous owner, but I made it safe and sound none the less.

    Thank you

  4. #4
    CB750 Guru amc49's Avatar
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    Yes, at that mileage. Aircooled engines wear faster than liquid cooled ones do and why the water cooled engines in bikes last so much longer now. Here in Texas the guys who did the police bikes if they were Japanese aircooled fours recommend a complete overhaul at 50K miles. The newer ones go much longer, the idle time in traffic just killed the old ones.

    I've seen a few DOHC 900s make 80K miles and one that made 100 and all were in lower temp places like you, I still wonder how they went so long. Here in Texas you don't have a prayer of doing that.

  5. #5
    CB750 Member Longer's Avatar
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    Wow, I guess I have my work cut out for me then. A little nervous, but excited to get to it.

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