How do I verify TDC on a cylinder?
Thread Starter
|
Seasoned HDF Member
Joined: Nov 2006
Posts: 5,895
Likes: 1,908
From: East Coast, USA
I have another question. When I align both timing marks on the crank and cam sprocket to get TDC on the rear cylinder, should both lifters for that cylinder be at their lowest point? When I looked inside the lifter cover, it looked like one lifter was slightly higher than the other one (which seemed to be at it's lowest point).
Thread Starter
|
Seasoned HDF Member
Joined: Nov 2006
Posts: 5,895
Likes: 1,908
From: East Coast, USA
Wow! A perfect example of Occam's razor.
Yes! I guess when I installed the lifter (I coated it with oil), it didn't fall all the way into the passageway. Now, with the timing marks on the crank and cam sprocket aligned, the lifters are at their lowest point and on the base circle of the cam. Thank you!
Yes! I guess when I installed the lifter (I coated it with oil), it didn't fall all the way into the passageway. Now, with the timing marks on the crank and cam sprocket aligned, the lifters are at their lowest point and on the base circle of the cam. Thank you!
Stellar HDF Member
Joined: Sep 2017
Posts: 2,144
Likes: 577
From: memphis
this is how i do it:
remove the plugs
place in 6th gear
place a straw in the cylinder you are working on
turn the rear tire until straw shoots out of the cylinder
retrieve straw from the other side of the garage
insert straw into the cylinder and feel for the piston
rock rear wheel to bring the piston back to the top
repeat on other cylinder
remove the plugs
place in 6th gear
place a straw in the cylinder you are working on
turn the rear tire until straw shoots out of the cylinder
retrieve straw from the other side of the garage
insert straw into the cylinder and feel for the piston
rock rear wheel to bring the piston back to the top
repeat on other cylinder
Seasoned HDF Member
Joined: Mar 2010
Posts: 21,123
Likes: 7,643
From: Poolville
Whatever happened to just watching the rear cylinder intake and exhaust lifters going to overlap, which would be spin the motor over with the rear wheel in 6th gear watch the intake lifter come up and go down. continue spinning the rear wheel to watch the exhaust lifter go up an them start to go down.. as the exhaust lifter on the rear cylinder starts to go down you will see the intake lifter starting to come up at the same time, This would be the overlap.. stop spinning the rear wheels when the two lifters are even in the lifter bores stop turning the wheel and at this point you can install an adjust the front push rods to their desired preload any wears from 0.125" to 0.140".... To do the rear cylinder you would put the front cylinder in overlap the same way and then install an adjust the rear cylinder pushrods.. no guessing..
Thread Starter
|
Seasoned HDF Member
Joined: Nov 2006
Posts: 5,895
Likes: 1,908
From: East Coast, USA
this is how i do it:
remove the plugs
place in 6th gear
place a straw in the cylinder you are working on
turn the rear tire until straw shoots out of the cylinder
retrieve straw from the other side of the garage
insert straw into the cylinder and feel for the piston
rock rear wheel to bring the piston back to the top
repeat on other cylinder
remove the plugs
place in 6th gear
place a straw in the cylinder you are working on
turn the rear tire until straw shoots out of the cylinder
retrieve straw from the other side of the garage
insert straw into the cylinder and feel for the piston
rock rear wheel to bring the piston back to the top
repeat on other cylinder
I'm not understanding how this above procedure ensures that TDC is on the compression stroke.
Whatever happened to just watching the rear cylinder intake and exhaust lifters going to overlap, which would be spin the motor over with the rear wheel in 6th gear watch the intake lifter come up and go down. continue spinning the rear wheel to watch the exhaust lifter go up an them start to go down.. as the exhaust lifter on the rear cylinder starts to go down you will see the intake lifter starting to come up at the same time, This would be the overlap.. stop spinning the rear wheels when the two lifters are even in the lifter bores stop turning the wheel and at this point you can install an adjust the front push rods to their desired preload any wears from 0.125" to 0.140".... To do the rear cylinder you would put the front cylinder in overlap the same way and then install an adjust the rear cylinder pushrods.. no guessing..
Anyways, I got it done.
I'd like to thank everyone for their help!
Seasoned HDF Member
Joined: Mar 2010
Posts: 21,123
Likes: 7,643
From: Poolville
@memphisharley
I'm not understanding how this above procedure ensures that TDC is on the compression stroke.
It's just a lack of confidence on my ability since I have very little experience in this area. The fear of adjusting the pushrods while the piston isn't at TDC on the compression stroke is rather large. Also, working with the bike on a motorcycle jack, I'm on the floor, trying to spin the rear wheel and place my fingers inside the lifters is a job for a contortionist. If I had a helper, this would be much easier.
Anyways, I got it done.
I'd like to thank everyone for their help!
I'm not understanding how this above procedure ensures that TDC is on the compression stroke.
It's just a lack of confidence on my ability since I have very little experience in this area. The fear of adjusting the pushrods while the piston isn't at TDC on the compression stroke is rather large. Also, working with the bike on a motorcycle jack, I'm on the floor, trying to spin the rear wheel and place my fingers inside the lifters is a job for a contortionist. If I had a helper, this would be much easier.
Anyways, I got it done.
I'd like to thank everyone for their help!
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
6 Weirdest Harley-Davidsons Ever Sold to the Public
Verdad Gallardo
7 Times Harley-Davidson Chucked Tradition Out the Window
Verdad Gallardo
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
Stellar HDF Member
Joined: Sep 2017
Posts: 2,144
Likes: 577
From: memphis
@memphisharley
I'm not understanding how this above procedure ensures that TDC is on the compression stroke.
I'm not understanding how this above procedure ensures that TDC is on the compression stroke.
Seasoned HDF Member
Joined: Mar 2021
Posts: 18,496
Likes: 3,729
From: backwoods
When tearing an engine down i stick my finger in hole to feel pressure. Also do straw. I then feel pushrods spin freely with no tension
They use to make something that would screw in spark plug hole and rise and fall . Waste of money to some. But would be cool gizmo