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Thread: Rebuilt top end, no start

  1. #1
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    Default Rebuilt top end, no start

    Hey guys. This has been an incredibly slow project with lot of pauses, so I probably missed something along the way.

    I put a new cam, chain, heads, intake, etc. Cam installed at zero, no advance no retard.

    I thought I marked the distributor and brackets correct but maybe not.

    It has spark, it has fuel, so it is probably a timing issue.

    Theres no piston to valve contact, and I want to assume the cam is good (zeros lined up).

    With the harmonic balancer at TDC, the distributor was 180 degrees off. Ok. I took it out, rotated the tooth, and now at TDC the rotor is pointing to #1.

    I thought I am golden now, but no dice. I pulled plug out and it does fire, but I dont have a timing gun to see if it fires at TDC.

    As long as rotor is approx at #1, fuel sync should be close enough? I had zero issues when doing this build 15 years ago.

    I did have to grind the distributor clamp down because I couldnt tighten it with the distributor at #1 - I probably am off a tooth on the gear when I did the cam install. But as long as the rotor is at #1 at TDC, it doesnt matter right?

    Sorry for the primitive questions. I am too busy with work these days and have no more time for projects, and just need to put this back together.

    Thanks.

  2. #2

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    One tooth off on a cam gear could mean as much as 17* either way.

    Here's an old trick you can use...well... I used back in the day. . There's a plug (piston stop) you can insert in the spark plug hole to tell you you've reached tdc if you're having trouble otherwise.. You can use a straw here as well but as the piston starts to come up and hit the plug or straw, mark the balancer. Turn the crank the other way until it hits the stop again. Mark the balancer again. The exact center of these two marks is your tdc.

    I've seen engines not start with a tooth off. I've seen engines start and run shitty. I've seen engines run fine all the way up to 3-4K rpm and then crap out.
    Last edited by arro222; 02-23-2021 at 11:09 PM.

  3. #3
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    fixed! distributir was 180 off.. harmonic balancer hits tdc twice.. duh

    thank you folks!

  4. #4

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    Quote Originally Posted by spawn_x View Post
    fixed! distributir was 180 off.. harmonic balancer hits tdc twice.. duh

    thank you folks!
    I thought you had already turned it around and still no joy.

  5. #5
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    Quote Originally Posted by arro222 View Post
    I thought you had already turned it around and still no joy.
    Thats what I thought, but I guess it was off the first time around. I didnt check it after putting it back together, jist fired up, no go, aligned tdc and moved rotor shaft about 180, still no go, then did the same thing again, and it fired right up.

    It was probably off a cam tooth gear like you mentioned.

    Thanks man!

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