CB 360 74 Fresh rebuilt Tapping noise - Page 2
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Thread: CB 360 74 Fresh rebuilt Tapping noise

  1. #11
    Supporting Member crazypj's Avatar
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    That's a knock not tapping. If springs and magnets are not 'pulling' I would look at cam timing. It's very easy to get one tooth out. You can do a quick check by removing points cover, points plate and points cam. Rotate to TDC and look at the locating pin position. It should be either straight up or straight down lining up with centre of cylinder. It's easy fix if out, top engine mount and cam cover only, about 30 mins
    There are three types of people in the world, those who can count and those who can't
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  2. #12
    Member Yakoza09's Avatar
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    i checked as you said and it seems like you was right and that dot on camshaft is slightly off....do i have to open engine cover and fix it with that small gear wheel on the camshaft? or is there any more simple way ?

    do you think this may be the issue?

    if this will be fixed and i will again adjust camchain, valves and timing it may be fine?
    i hope so

    i will try tomorrow

    thanks for staying with me and for your help. i will let you know if it was the issue or not !!


    CB 360 74 Fresh rebuilt Tapping noise-img_7741-copy.jpg

  3. #13
    Sensei 66Sprint's Avatar
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    Why is your Crankshaft pictured at ~90 degrees past left TDC?...

    At that pictured position, the "pin" SHOULD be 45 degrees past the cam to crank centerline.....
    (and it looks close...Hard to be accurate at pictured angle)
    Last edited by 66Sprint; 05-16-2019 at 01:57 PM.
    "I have a mind like a steel trap.....Old and rusty, of antiquated design, and hard to get stuff back out of...."
    Contact info: E-mail; [email protected] Phone; 540-525-5199

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  5. #14
    Member Yakoza09's Avatar
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    sorry i uploaded wrong image
    here is correct one

    well if it supposed to be 45 degrees than i think its not...

    that "pin" should be 45 degree or 90 degree as pj said?


    CB 360 74 Fresh rebuilt Tapping noise-img_7741-copy.jpg
    Last edited by Yakoza09; 05-16-2019 at 02:33 PM.

  6. #15
    Sensei 66Sprint's Avatar
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    Based on the second set of pix, the cam to crank timing is definitely off by at least a tooth.....
    With crank at LT, the "pin" should be on the centerline between cam and crank (centerline of the cylinder), either at top or bottom.....
    Last edited by 66Sprint; 05-16-2019 at 02:58 PM.
    "I have a mind like a steel trap.....Old and rusty, of antiquated design, and hard to get stuff back out of...."
    Contact info: E-mail; [email protected] Phone; 540-525-5199

  7. #16
    Member Yakoza09's Avatar
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    how do you guys know such a little things?

    ok cool, i will have to fix it than. do you think that that tapping or knocking sound may be caused by this?

  8. #17
    Supporting Member crazypj's Avatar
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    Quote Originally Posted by Yakoza09 View Post
    sorry i uploaded wrong image
    here is correct one

    well if it supposed to be 45 degrees than i think its not...

    that "pin" should be 45 degree or 90 degree as pj said?


    Click image for larger version. 

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    That's at LT, Pin is closer to 7:00 than 6:00 o'clock so advanced one tooth. You didn't pull front run of chain tight when fitting sprocket to cam. (kinda rotate sprocket backwards) You have to pull cam cover to fix it. Easiest thing to do is remove cam cover, remove both sprocket bolts and 'walk' chain around sprocket. If you used any on the 'bonds' (Honda, Suzuki, etc) clean up should be minimal and entire thing done in about an hour. As 'everyone' knows DON'T USE SILICON SEALER Oh, as for your question, I was messing with these things when they were current model's and was working in a Honda dealers just after the CJ250/360 was discontinued. After 50 yrs working on bikes/engines you kinda pick up a few idea's The 10,000 hrs to become an expert seems to be pretty true?
    Last edited by crazypj; 05-16-2019 at 11:18 PM.
    ancientdad likes this.
    There are three types of people in the world, those who can count and those who can't
    I'm not a complete idiot, but, I'm working on it

  9. #18
    Senior Member Erwin's Avatar
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    Quote Originally Posted by Yakoza09 View Post
    how do you guys know such a little things?
    Experience! The experience of making the same mistake in the past. It'll teach you to recognize the sound of a piston hitting a valve pretty fast.
    1972 CB350K3 General Export | 1976 CB200T K0

  10. #19
    Sensei 66Sprint's Avatar
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    My first response was to the rotor pictured at ~90 degrees past LT which should have placed the pin 45 degrees past.... It measured ~34 degrees , so that made the pin about 11 degrees late....
    Since the upper sprocket has 34 teeth in its 360 degree circle, each tooth represents 10.588 degrees, that made it close enough (due to picture angle, etc) that the ~11 degrees meant one tooth off.....
    The second set of pix with the crank actually at LT also showed the same ~11 degree discrepancy, so it verified the one CAMSHAFT tooth retarded error.....
    I know PJ said advanced, but since you would have to turn the crank further than LT ( in a CCW rotation) to put the pin in its proper vertical centerline location, It can be described as the crankshaft is advanced or as the camshaft is retarded..... I used the latter as the crank will remain held at LT while you will rotate the cam sprocket/camshaft, advancing it to effect the correction.....
    PJ IS more familiar with this engine, so I'll let him advise on the likelihood the valve detrimentally "kissed" a piston while one tooth out..... IF so, I'd pull the head and inspect it as well......
    Last edited by 66Sprint; 05-17-2019 at 04:01 AM.
    "I have a mind like a steel trap.....Old and rusty, of antiquated design, and hard to get stuff back out of...."
    Contact info: E-mail; [email protected] Phone; 540-525-5199

  11. #20
    Supporting Member crazypj's Avatar
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    It kept running on both cylinders, exhaust valve should be OK. If it was only running on one cylinder it's pretty certain bent and will have to be changed. 7mm stem on 28mm valve is pretty robust. Swapping it for a new one is 'correct' thing to do but in my experience the exhaust valve should be OK to stock red-line if OP doesn't want to remove head. I don't remember ever seeing a 360 'drop a valve' even after piston cut away has been re-shaped. ( you only find the dents when cam bearings fail and your cleaning everything) Oh, The valve probably does have a slight tweak but it would only be measurable on a v-block with DTI or valve run out gauge. In normal backyard shop (and many dealers) it wouldn't be noticeable. I've seen 350's and 360's run for thousands of miles with 'bent' exhaust valves. It's a case of what you don't know can't hurt you, when I know about it I can't help myself and have to change them. Even in a 'race' motor it's kinda normal (until you get to a pretty high level and can afford to check everything twice)
    Last edited by crazypj; 05-17-2019 at 11:48 AM.
    There are three types of people in the world, those who can count and those who can't
    I'm not a complete idiot, but, I'm working on it

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