Shovel head help
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Stage I
Joined: May 2019
Posts: 1
Likes: 0
From: Chicago, il
Shovel head help
Hey brothers,
I've got a 1981 harley flh, my fathers bike passed on to me, I've been making it mine for the past year and am having some troubles with exhaust leaking from the rocker arms while trying to start it. On the exhaust stroke I can feel air escaping out. I'm unsure if it's just the seals I need to replace or the rocker arm itself. There is oil at the base of the rocker arm leaking out too, what are your thoughts on which to do, should i bite the bullet and do all of it or just try to seals first? Tha is for the help fellas.
I've got a 1981 harley flh, my fathers bike passed on to me, I've been making it mine for the past year and am having some troubles with exhaust leaking from the rocker arms while trying to start it. On the exhaust stroke I can feel air escaping out. I'm unsure if it's just the seals I need to replace or the rocker arm itself. There is oil at the base of the rocker arm leaking out too, what are your thoughts on which to do, should i bite the bullet and do all of it or just try to seals first? Tha is for the help fellas.
Seasoned HDF Member
Joined: Apr 2012
Posts: 9,980
Likes: 5,218
From: Michigan
U need to determine if you may simply have an exhaust gasket or a head pipe leaking or if it is a more serious engine issue,
A cylinder "compression check" could help determine if you have a leakage.
You also need to take a look at your spark plugs to see if they are presenting signs of oil residue.
You didn't say how many miles are on the engine but if you do have a compression issue you're probably due for a complete upper-end rebuild and you'd need to find some that has experience in rebuilding Shovelheads.
My cousin has done his '75 Shovel twice and he says it's a pretty simple job if you're mechanically inclined and have the time and tools.
Another cousin has an '82 Low-Rider and he's had his upper end done once and his 4spd trans rebuilt twice.
These engines don't have the longevity of the EVO's and T/C's and they require more maintenance.
I had about 38,000 miles on my '76 Super-Glide (when stolen) and it ran great and the engine was never touched but I had an external oil cooler and an additional externa spin-on filter, and I used 50w Valvoline Racing motor oil in it most of the time and 60w during the summer months. (This was back before synthetic oils came along).
A cylinder "compression check" could help determine if you have a leakage.
You also need to take a look at your spark plugs to see if they are presenting signs of oil residue.
You didn't say how many miles are on the engine but if you do have a compression issue you're probably due for a complete upper-end rebuild and you'd need to find some that has experience in rebuilding Shovelheads.
My cousin has done his '75 Shovel twice and he says it's a pretty simple job if you're mechanically inclined and have the time and tools.
Another cousin has an '82 Low-Rider and he's had his upper end done once and his 4spd trans rebuilt twice.
These engines don't have the longevity of the EVO's and T/C's and they require more maintenance.
I had about 38,000 miles on my '76 Super-Glide (when stolen) and it ran great and the engine was never touched but I had an external oil cooler and an additional externa spin-on filter, and I used 50w Valvoline Racing motor oil in it most of the time and 60w during the summer months. (This was back before synthetic oils came along).
Seasoned HDF Member
Joined: Jun 2006
Posts: 28,520
Likes: 3,953
From: Vermont
Pressure can only escape if the effin nut on the heffer shaft isnt tightened to proper torque specs.
Compression check first. Best case, what you've got is a bad seal between the exhaust pipe and the cylinder head. Easy fix. Worst case (probably) is you've got a blown head gasket.
Anything more than 10% or 15% diff between cylinders on the test means it's coming apart.
Not knowing the history of the motor, I will say that a complete top end rebuild is basic periodic maintenance on shovels. If you don't know when (or if) it was last done to this bike, and if you want it to be a reliable rider, may as well dig in and do it now.
If you go that way, do it once and do it right. Send the heads out for new valves, guides, seats, springs (maybe) and seals. Get the cylinders honed. Certainly new rings. Maybe new pistons while you're at it. Modern MLS gaskets. Etc.
And some terminology:
- The exhaust pipes connect to the cylinder heads.
- The cylinder head is mounted on top of the cylinder. Between them is the Head Gasket.
- The rocker box mounts on top of the cylinder head.
- The rocker arms are inside the rocker boxes, and mechanically connect the push rods to the intake and exhaust valves.
Anything more than 10% or 15% diff between cylinders on the test means it's coming apart.
Not knowing the history of the motor, I will say that a complete top end rebuild is basic periodic maintenance on shovels. If you don't know when (or if) it was last done to this bike, and if you want it to be a reliable rider, may as well dig in and do it now.
If you go that way, do it once and do it right. Send the heads out for new valves, guides, seats, springs (maybe) and seals. Get the cylinders honed. Certainly new rings. Maybe new pistons while you're at it. Modern MLS gaskets. Etc.
And some terminology:
- The exhaust pipes connect to the cylinder heads.
- The cylinder head is mounted on top of the cylinder. Between them is the Head Gasket.
- The rocker box mounts on top of the cylinder head.
- The rocker arms are inside the rocker boxes, and mechanically connect the push rods to the intake and exhaust valves.
Last edited by 0maha; May 4, 2019 at 12:58 PM.
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Road Warrior
Joined: Aug 2008
Posts: 1,306
Likes: 864
From: Sheboygan, WI
You're going to have to do a better job of describing where your leak is, or post a picture with you pointing at it or something.
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