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  1. #1
    CB750 New Member Fatherof2's Avatar
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    Slight stumble at the bottom of 1st - 3rd gear.

    Hi Gang,

    First post! I just bought a 93 NH750. 22K miles, 1200 bucks. Bike is in pretty nice shape overall.

    I have not put many miles on it yet, but I notice that the bike kind of hesitates at the bottom of 1st - 3rd gear. When I start off in first, there is a slight hesitation and then when I get to the top of the gear and shift to 2nd, it hesitates again until I get further up into the gear. Same thing going into 3rd. Once I get higher in the powerband, it goes away and the bike really starts to move.

    Bike starts fine and idles fine with the choke off, so I figure the pilot jets are OK.

    Any thoughts on the hesitation?

    Thank you very much,

    David

  2. #2
    CB750 New Member Fatherof2's Avatar
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    So I just went for another quick ride to try to sort this out.

    The bike runs MUCH better with the choke all the way on. It advances the idle so that there is power right away at the bottom of first, second and third gear.

    To me this usually means a clogged pilot jet, but the bike starts easily when cold with the choke on and then I shut the choke off immediately after it starts and the bike idles just fine.

    In doing some research, I came across a thread about putting a washer under each needle to give it the affect of raising the clip if you will. Is this my problem, or do I have a clogged pilot or two?

    Any thoughts?

    Thanks All!

  3. #3
    CB750 Guru amc49's Avatar
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    Carb issue of some sort. There is no way the bike should run right with choke full on. If bike is stock with stock pipes you don't go lifting the needles up either. That's one of the ones with all the vacuum emission crap on it, a possible indicator of a vacuum leak.

  4. #4
    CB750 New Member Fatherof2's Avatar
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    Thanks amc!

    Bike is bone stock. I will pull the carbs and start cleaning.

    Do you recommend a carb rebuild kit, or just put everything in the ultrasonic cleaner?

    Thanks again!

  5. #5
    CB750 Guru amc49's Avatar
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    I recommend checking each and every hole for being open like they need to be. Cleaning does nothing if not checked for result. I say that after much time on early DOHC which often has to be cleaned several times by others to get them fixed. The idle ports and any passages to transfers often clog and where you cannot prove them out easily.

    Service manual here to understand the emissions system and all the hoses..........

    https://moto-odejda.ru/file/HondaNithawk.pdf

  6. #6
    CB750 New Member Fatherof2's Avatar
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    Damn! Now the whole thing sounds daunting!

    Thanks for the manual!!

  7. #7
    CB750 Guru amc49's Avatar
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    I'd say it's not hard at all but that's after doing about 500 carbs of every type. It's not normal to pay that much attention to holes unless you are a gigolo.

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