Ignition Problem
Cruiser
Joined: Dec 2007
Posts: 213
Likes: 2
Unless someone tells me that my one coil is two coils wrapped up as one?
Yes, I have NO compression in the front cylinder. It kind of sucks because just replaced the pistons. I just adjusted the intake pushrod as it was not near long enough (I have adjustable pushrods).
So the next move is obviously to pull the fron head off and inspect the valves I'm assuming. If it's in need of any machining I'm then going to have to remove the back cylinder as well so the machining work matches, or should I leave it because the compression is good?
Where should I start with the heads? I'm also going to check the exhaust pushrod and make sure it's not too long and not allowing the valve to close.
So the next move is obviously to pull the fron head off and inspect the valves I'm assuming. If it's in need of any machining I'm then going to have to remove the back cylinder as well so the machining work matches, or should I leave it because the compression is good?
Where should I start with the heads? I'm also going to check the exhaust pushrod and make sure it's not too long and not allowing the valve to close.
Seasoned HDF Member
Joined: Aug 2007
Posts: 8,199
Likes: 3,087
From: NW AR
Sucks to be right. It's a curse.
Anyway, glad you found the problem. I would just pull the front head and see if you can find exactly what the problem is and fix that. Could be just a bad valve or guide or seat. I wouldn't worry about the back head matching perfectly. There's too many variables in this anyway, and unless you're going for a top fuel drag bike, it probably wouldn't make any difference.
Anyway, glad you found the problem. I would just pull the front head and see if you can find exactly what the problem is and fix that. Could be just a bad valve or guide or seat. I wouldn't worry about the back head matching perfectly. There's too many variables in this anyway, and unless you're going for a top fuel drag bike, it probably wouldn't make any difference.
Advanced
Joined: Jan 2012
Posts: 87
Likes: 3
From: elko nevada
dont waste a gasket yet. pull the intake and exhaust off front cylinder, fill them both with gasoline and see (threw the spark plug hole) if either drip gas in the motor. if the gas evaporates insteady of going in the motor, you might have slight valve leak but not enough for zero compression.
more likely to be a pushrod problem. most will probably disagree with me and say this will put unnecessary strain on your valve springs, but adjust your pushrods till they open the valves, let them sit for a few hours (to be 101% sure the lifters are completely bleed off) then readjust pushrods to manufacturer specs.
another thing i do differently that alot of people would disagree with me on, is run a real heavy oil for a few days and re break in the top end, heavy oil will help slow down blow by and let the rings begin to seal under less stress, after 100 miles or so change the oil to 20-50 to complete the break in process.
like i said alot of people will disagree, but if your building your own top end its probably cause your just like me and your budget doesnt include hd labor costs.
more likely to be a pushrod problem. most will probably disagree with me and say this will put unnecessary strain on your valve springs, but adjust your pushrods till they open the valves, let them sit for a few hours (to be 101% sure the lifters are completely bleed off) then readjust pushrods to manufacturer specs.
another thing i do differently that alot of people would disagree with me on, is run a real heavy oil for a few days and re break in the top end, heavy oil will help slow down blow by and let the rings begin to seal under less stress, after 100 miles or so change the oil to 20-50 to complete the break in process.
like i said alot of people will disagree, but if your building your own top end its probably cause your just like me and your budget doesnt include hd labor costs.
Thanks Dr. Hess & ta2dup,
You guys have been a big help. And yes, I do all my own work because Harley's $85 an hour is just too high in my eyes, and I love working on motors. I was raised by a master mechanic who used to drag race... I have been actually wrenching on cars since I was 6 years old, and that's not a lie. It was under the supervision of my dad, but I was still doing it. It's a lot of memories that I will live with until I die. But there are still a lot of tricks that I don't know.
With all the electrical tests I've done on this bike, I would have sworn it was an electrical problem.
Thanks again guys
You guys have been a big help. And yes, I do all my own work because Harley's $85 an hour is just too high in my eyes, and I love working on motors. I was raised by a master mechanic who used to drag race... I have been actually wrenching on cars since I was 6 years old, and that's not a lie. It was under the supervision of my dad, but I was still doing it. It's a lot of memories that I will live with until I die. But there are still a lot of tricks that I don't know.
With all the electrical tests I've done on this bike, I would have sworn it was an electrical problem.
Thanks again guys
Elite HDF Member
Joined: Sep 2007
Posts: 4,468
Likes: 12
From: Bluffton, South Carolina
If you just replaced the pistons, take the spark plug out and look inside the cylinder. You may have had a circlip come loose and scored a cylinder. Lets hope it's valve related as it is much cheaper to replace.
John
John
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Advanced
Joined: Jan 2012
Posts: 87
Likes: 3
From: elko nevada
another option that you might find once it narrows down is a bad lifter.
this isnt a diagram of a harley lifter, just a basic hydraulic lifter, evos have hydraulic lifters that do wear out and go bad.
this isnt a diagram of a harley lifter, just a basic hydraulic lifter, evos have hydraulic lifters that do wear out and go bad.
Miacycles, Well I hope that didn't happen. I just put in a new set of KB 10.5:1 pistons that were .030 over. So if that did happen I'm screwed... I however, don't think that is the case.
Jim Kraft, I don't think it is the gasket. I put new James gaskets and torqued them to spec.
I'm just hoping it's not a valve issue.
Jim Kraft, I don't think it is the gasket. I put new James gaskets and torqued them to spec.
I'm just hoping it's not a valve issue.