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30% of the way there...

Discussion in 'Hangout Lounge' started by Zoot_Suit, Jan 5, 2024.

  1. Roast644

    Roast644 Well-Known Member

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    A shot in the dark maybe, but since you did a full teardown, did the TDC indicator bracket by the coil pickups get disturbed? Or did you check it's position with a dial indicator?
     
  2. Zoot_Suit

    Zoot_Suit Active Member

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    No, it didn't get bumped or moved, then I did verify with a dial indicator that it was where it had to be.

    I'll be wrenching on it in about a half hour here, it 'should' be running tonight...
     
  3. Zoot_Suit

    Zoot_Suit Active Member

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    Help me understand...

    Valves.png
     
  4. Franz

    Franz Well-Known Member

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    Is the inlet cam on the exhaust side and vice versa?
     
  5. chris123

    chris123 Active Member

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    Do you have a running bike that you can compression test with the same equipment?

    I was getting odd results on my one of my bikes. I decided to run a compression test on another running bike with the same method and Equipment. I ended up with getting the same odd results and decided to disregard the information. I ended up finding that the enrichment jets in the bowls of my carbs were plugged.
    Once I fixed this the bike started right up.
     
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  6. Zoot_Suit

    Zoot_Suit Active Member

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    The cams are in the correct positions, I quadruple checked.

    I know with forty-seven trillion percent accuracy that this is not a carburetor issue as they're sitting on a different workbench twelve feet away from the bike.

    However, when I get back to the shop later today I will test the compression tester on a different engine to verify that it's accurate.
     
  7. chris123

    chris123 Active Member

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    Sounds good.

    In my previous post I was just sharing my personal experience. I wasn’t trying to insinuate that your carbs are (or are not) the issue.
     
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  8. Minimutly

    Minimutly Well-Known Member

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    Well, if your cams are correctly set, your valve clearances exist (bet better still in spec), you have spark, and the carbs are correct it will run. If not who's products will you rubbish then?
     
  9. Huntchuks

    Huntchuks Well-Known Member

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    I think valve clearances have to be very tight, at least so that no feeler can be used, for it to affect compression. I'm still in the defective gauges camp. As for carbs and the bike starting problems, if they are clean and the starter jets in the float bowls are not clogged, the bike should at least start (if mixture screws are at a good starting position).
     
  10. Dan Gardner

    Dan Gardner Well-Known Member Premium Member

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    Assuming everything else is correct, there can only be three possibilities that I can think of - or some combination of the three:

    1. Bad gauge
    2. Valves - bad seats
    3. Leakage at the cylinder wall (rings and or surface)

    If it were me, the first possibility to eliminate is #1. Test it on a known good engine or get a different tester.

    Once that possibility is eliminated, the next step would be the old school test of adding oil to the cylinders and see if it effects compression. In theory, if the compression improves it points to the cylinder wall surface or rings, if it does not improve it points to something wrong with the valves - and since lash is correct, it must either be bad seats or incorrect timing

    That’s my $.02 at this point
     
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  11. Franz

    Franz Well-Known Member

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    Leakdown test.
     
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  12. Zoot_Suit

    Zoot_Suit Active Member

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    I didn't get around to wrenching on it yesterday I took down a 60 foot maple tree, by myself, in the heat. By the time I was finished I was beat and sunburnt to a crisp. But it was posing a safety risk so it had to take priority.
     
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  13. Minimutly

    Minimutly Well-Known Member

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    This only addresses the supposed issue with low compression. Go back to the original issue of not running on idle jets (bike only runs on full throttle), which absolutely points to the main jets only working. ie holding the throttle open makes the enrichment circuit (from main jet) work, and over 3000rpm you are on main jet anyway. So the primary/idle jet is not working - on all carbs, so that tells me the idle jets are wrong. I don't deny the valve clearances need to be right, but there are many bikes out there with tight exhaust valves running reasonably right. If the inlet valves aren't sealing that is another matter, but is this the case?
     
  14. Zoot_Suit

    Zoot_Suit Active Member

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    I have an acquaintance that said he'd take a look at it... one day. He's working 12 hours a day, 6 days a week right now, and he lives an hour away. So I'm not going to pressure him on his only day he really has to spend with his family.
     
  15. Roast644

    Roast644 Well-Known Member

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    Sometimes taking a break from a frustrating project is the best thing. The answer will click and it will be a great bike.
     
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  16. Zoot_Suit

    Zoot_Suit Active Member

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    A contractor that works for me has already offered to buy it, as is. Because he likes how well I did everything else on the bike. But I don't think I'd feel comfortable selling him a non-working nightmare.

    I'm debating on setting a deadline for it to be up and running, or crushing it with a front end loader so it can't cause anyone else anymore grief.
     
  17. Franz

    Franz Well-Known Member

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    Persevere you will get it fixed.
     
  18. Minimutly

    Minimutly Well-Known Member

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    Stop debating and grow up. Or should that be grow up and stop debating?
    Anyway -
    Do your pistons have rings fitted - tick surely?
    Do you have valve clearances - I've not taken the time to read through the stuff you posted, but tick?
    When you turn the engine over by hand, on no1 or 4 pot, does your inlet valve open at or just before tdc, close just after bdc, and as you get towards tdc both valves fully closed? Then stay closed until bdc when the exh valve opens? tick?
    We know you have spark, we've heard it, tick.

    If all these are ticked, swallow your pride and box up your carbs and send to the resident carb expert over there, maybe post a question on who would do them for you, they will be back in a week, maybe two, cost you peanuts, and lo, your bike will run, and you can (deservedly) enjoy all the hard work you've put into it.
    Or, strip them, with pics posted here, starting with the complete rack as removed, and someone will spot your error.
    Better than having, or repeatedly threatening to have a tantrum and scrap a nice bike.
    Just my 2 pence worth....
     
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  19. Zoot_Suit

    Zoot_Suit Active Member

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    I appreciate your input, but for the love of everything holy and sacred STOP asking and/or insisting about the carburetors that aren't even on the bike! I can assure you with forty-seven trillion percent accuracy that it's not the carburetors.

    And frankly, it is my bike, and if I want to crush it with a front end loader, I will.
     
  20. Zoot_Suit

    Zoot_Suit Active Member

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    Results of the leak down test...

    These readings are after ten minutes on each cylinder.

    But, I'm not experienced with performing these test.

    I heard minor air leakage, and I don't know if I performed the test correctly.

    I set it at 100psi.

    The minor air leakage I heard wasn't even enough to blow cigarette smoke around.

    Snapchat-1982154843.jpg
     
    Last edited: Jun 23, 2024
    Huntchuks and Franz like this.

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