pushrod adjustment
HDF Community Team
Joined: Dec 2005
Posts: 5,404
Likes: 2,605
From: NC USA
Ugh. No, I am not going to forget everything I have seen on youtube, that is just plain ridiculous, period. There are some excellent channels from very experienced and competent builders if you look. And I wasn't asking how to adjust lifters, or what cams need which rods. I am asking about the oil in hydraulic lifters.
Forget what I have, it's not important. I would like to know is: if a bike has been sitting a while with a lifter on a cam lobe holding open a valve all day, I would expect it to be bled down from the pushrod pressure, just as it does a while after you've adjusted it. Isn't this why some bikes tap some when started cold until the lifters pump up? So if it is already bled down, what happens when you put that lifter on a cam heel and take up the slack before putting the proper number of flats on it? This is where I become confused.
If this has already been explained, please tell me again. Can be hard to pull the useful and to the point info from the noise sometimes.
Forget what I have, it's not important. I would like to know is: if a bike has been sitting a while with a lifter on a cam lobe holding open a valve all day, I would expect it to be bled down from the pushrod pressure, just as it does a while after you've adjusted it. Isn't this why some bikes tap some when started cold until the lifters pump up? So if it is already bled down, what happens when you put that lifter on a cam heel and take up the slack before putting the proper number of flats on it? This is where I become confused.
If this has already been explained, please tell me again. Can be hard to pull the useful and to the point info from the noise sometimes.
There is a spring inside the tappet that will hold enough pressure to adjust it correctly even if it leaked down. Others may open a valve while extending the push rod. That situation requires you wait until that valve bleeds off before proceeding.
If this doesn't explain it to your understanding, I suggest you get into the job and post again if you run into issues or have questions..
Seasoned HDF Member
Joined: Dec 2010
Posts: 7,736
Likes: 1,524
From: Coromandel Peninsula New Zealand
Ugh. No, I am not going to forget everything I have seen on youtube, that is just plain ridiculous, period. There are some excellent channels from very experienced and competent builders if you look. And I wasn't asking how to adjust lifters, or what cams need which rods. I am asking about the oil in hydraulic lifters.
Forget what I have, it's not important. I would like to know is: if a bike has been sitting a while with a lifter on a cam lobe holding open a valve all day, I would expect it to be bled down from the pushrod pressure, just as it does a while after you've adjusted it. Isn't this why some bikes tap some when started cold until the lifters pump up? So if it is already bled down, what happens when you put that lifter on a cam heel and take up the slack before putting the proper number of flats on it? This is where I become confused.
If this has already been explained, please tell me again. Can be hard to pull the useful and to the point info from the noise sometimes.
Forget what I have, it's not important. I would like to know is: if a bike has been sitting a while with a lifter on a cam lobe holding open a valve all day, I would expect it to be bled down from the pushrod pressure, just as it does a while after you've adjusted it. Isn't this why some bikes tap some when started cold until the lifters pump up? So if it is already bled down, what happens when you put that lifter on a cam heel and take up the slack before putting the proper number of flats on it? This is where I become confused.
If this has already been explained, please tell me again. Can be hard to pull the useful and to the point info from the noise sometimes.
Seasoned HDF Member
Joined: Dec 2010
Posts: 7,736
Likes: 1,524
From: Coromandel Peninsula New Zealand
?????? What do you mean? You can adjust from the bottom up on shovel but I have never done it nor heard of anybody who does.
Last edited by Spanners39; Sep 23, 2025 at 07:30 PM.
Seasoned HDF Member
Joined: Nov 2006
Posts: 12,878
Likes: 5,449
From: la la land jerzey
Yea i seen it done like that 50 years ago but everything was almost new and from Harley today who knows what’s in any engine
forget the bottom up adjustment i think it was 1 turn maybe i forget but many did it that way in the 60s and 70s
forget the bottom up adjustment i think it was 1 turn maybe i forget but many did it that way in the 60s and 70s
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