Rocker box question
Thread Starter
|
Road Warrior
Joined: May 2012
Posts: 1,388
Likes: 132
From: Baltimore, MD
Rocker box question
While waiting for my garage to be completed, I'm planning out the steps on my 1980 FXS-80 project. The engine runs rather well but, as you'd expect, leaks oil. I'm still diagnosing all the leak points but there are definitely leaks around the rocker box bolts on the front cylinder. And also around the front rocker box to cylinder head joint. Interestingly, I don't think I have any leaks between the jugs on either cylinder. So I'm thinking of pulling the rocker boxes off and cleaning them up, putting on new gaskets and properly torquing them.
Can I get the rocker boxes off without removing the whole engine from the frame? And also without splitting the jugs? At some point I'll split the jugs and do work on the rings and such, but I'm trying to do this job in smaller "pieces".
I'd like to strip the boxes of the bad, flaking paint job a prev owner did. (See pic).
Is there anything else I should be doing while I have them off - like valve work or remachining of the rocker box/cylinder mating face? I'm mostly concerned about the interface being crisp, since the whole point of this is to address an oil leak on an otherwise good-working engine.
Can I get the rocker boxes off without removing the whole engine from the frame? And also without splitting the jugs? At some point I'll split the jugs and do work on the rings and such, but I'm trying to do this job in smaller "pieces".
I'd like to strip the boxes of the bad, flaking paint job a prev owner did. (See pic).
Is there anything else I should be doing while I have them off - like valve work or remachining of the rocker box/cylinder mating face? I'm mostly concerned about the interface being crisp, since the whole point of this is to address an oil leak on an otherwise good-working engine.
Seasoned HDF Member
Joined: Oct 2005
Posts: 7,495
Likes: 3,705
From: Santa Klaus County, Cali
You need to take of the heads in order to get at the rocker boxes. Not necessary to pull the engine.
Just make sure you have both pistons at the low point and you don't how to worry about pistons and rings. Basically it's just tanks, carb and manifold, upper motot mount and pushrods to get at the heads
Just make sure you have both pistons at the low point and you don't how to worry about pistons and rings. Basically it's just tanks, carb and manifold, upper motot mount and pushrods to get at the heads
Thread Starter
|
Road Warrior
Joined: May 2012
Posts: 1,388
Likes: 132
From: Baltimore, MD
Originally Posted by panz4ever
You need to take of the heads in order to get at the rocker boxes. Not necessary to pull the engine.
Just make sure you have both pistons at the low point and you don't how to worry about pistons and rings. Basically it's just tanks, carb and manifold, upper motot mount and pushrods to get at the heads
Just make sure you have both pistons at the low point and you don't how to worry about pistons and rings. Basically it's just tanks, carb and manifold, upper motot mount and pushrods to get at the heads
And that answers the question about the head and rocker box interface. I suppose while I have them both off, I can inspect them and machine them if necessary, before putting in a new gasket and reinstalling.
Last edited by scooper321; Nov 26, 2017 at 11:09 AM.
Seasoned HDF Member
Joined: Nov 2006
Posts: 12,878
Likes: 5,449
From: la la land jerzey
have the rocker boxes fly cut flat it will save you doing this job again soon as the heat and years of service gets the alloy memory back in check
if they did use washers at some point and the stud hole tops look chewed then have them spotted as well so the torque is correct across the entire cover
if they did use washers at some point and the stud hole tops look chewed then have them spotted as well so the torque is correct across the entire cover
Cruiser
Joined: Jul 2017
Posts: 103
Likes: 18
From: NE Ohio
If you are pulling the heads and you don't know when the top end was gone through last, you might as well pull the cylinders too. This way you can get a look at the pistons, rings and wrist pins and refresh if needed. You can also get an idea on condition of the rod bearings.
Trending Topics
Thread Starter
|
Road Warrior
Joined: May 2012
Posts: 1,388
Likes: 132
From: Baltimore, MD
If you are pulling the heads and you don't know when the top end was gone through last, you might as well pull the cylinders too. This way you can get a look at the pistons, rings and wrist pins and refresh if needed. You can also get an idea on condition of the rod bearings.
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
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
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Thread Starter
|
Road Warrior
Joined: May 2012
Posts: 1,388
Likes: 132
From: Baltimore, MD
Fly cut... i know this is like milling. But what surface are you recommending i cut? The outside? Or the rocker/head interface?
Seasoned HDF Member
Joined: Nov 2006
Posts: 12,878
Likes: 5,449
From: la la land jerzey
the same place the gaskets go is the place they leak, if you take it to a machine shop use the correct terms I used to explain what you want, - fly cut and spot the nut locations and see what he says