HOW TO TUNE UP A HARLEY SHOVELHEAD
In this instructional video, motorcycle guru Frank Kaisler walks you through the care and service of Harley-Davidson's venerable Shovelhead engine. Frank shares hard-earned tips and tricks along with important information that have served him so well over the past four decades. Pair this video with a Harley service manual, one of the most important tools you should have in your garage!
He includes many aspects of engine and motorcycle tune & service which are covered in this video:
- Changing fluids
- Setting and servicing your ignition & ignition timing
- Caring for your fuel system
- Maintaining the valve train
- Electrical
- and tons more!
In addition to the knowledge and support we offer to motorcycle enthusiasts world-wide, we also have all of the high quality parts for Harleys that you need!
WATCH SHOVELHEAD TUNE & SERVICE VIDEO
Follow Frank's tips and tricks and you'll build the skills you need to resurrect that old project and keep your bike running strong, with confidence. There is over 2 hours of killer content here. Grab an adult beverage, grab some tools, get in the garage and get after it, Enjoy!
SHOVELHEAD TUNE & SERVICE VIDEO TRANSCRIPTION
Frank Kaisler: Hello, I'm Frank Kaisler, and today we're going to deal with Shovelhead motorcycles. Shovelhead power motorcycles have been around from '66 to '84. They're my favorite engine. I've ridden, fooled with, blown up, tore down, rebuilt, chromed everything in these engines for years and years. They're simple, they're easy to work on, there's no problem why yours can't run as good as mine. Let's get to it.
The first generation had generator cases so basically what the factory would do is they would change either the top end or the lower end of the motor. These lower ends had been produced in one form or another from Panhead from 1948 up to '84, it's just that in '66 they put a Shovelhead top end on instead of the Panhead. The reason it's called a Shovelhead top end is these rocker boxes. If you look at a flat shovel like a coal shovel, if anybody remembers what that is, and turned it over it would fit over the top of the rocket box like a glove, that's why it's considered a Shovelhead.
They featured internal drain back through the cases-- I mean, through the rocket boxes, through the heads, through the cylinders, into the lower end. It was fed via outside oil line up through the rocker boxes through each rocker arm shaft all the way forward. They built these from '66 to 1969. In 1970 they changed the lower ends and put an alternator on, which did away with this part of the engine case and exposed the other side of the case to a larger diameter where they would put the alternator.
Carburetor for Shovelheads. They came with a Tillotson one year, they came with a DC Linkert one year, then they went to the Bendix. Bendix was the most prolific. I forget what year it was, but they went to the Butterfly can and then to the CV. CV's, I think, were only last year. Around 1980 or '81 is when they went to what they call dual throttle carburetor. The reason for the dual carbo throttle, was somebody wrecked their bike, blamed the factory on the throttle didn't close so now they would go to a dual cable. One cable would open the carburetor, the other would pull it close.
You could hear the distinctive snap of the carburetor closing, that's because of a lawsuit, and that's the only reason. Every carburetor and every fuel injector system made since then has dual cables. It may look a little unsightly, but sometimes it's safe for people who don't really get the product of closing the throttle all the way. The outstanding carburetor, again, for performance on a Shovelhead, is this S&S. They made variations of this over the years from what they call the L series, which is an expanded version of the DC Linkert, which had a side bowl. They went to a B which was probably this much longer and would stick way out.
This being a Shorty E style, it comes with its own manifold that utilizes the stock o-rings and clamps, would fit on the heads like this-- Have an isolator block which we have here on a bench, and then the carburetor bolt-on like that. Tucks in nice and neat would have the big teardrop air cleaner. You'd get your leg around it which was one of the main faults of early model carburetors. They would stick so far out with the air cleaner, with the velocity stack, you couldn't get your leg around it to hit your brake pedal, or if you could you'd look like you walk bow legged.
All these S&S products are well supported by the company who's still in business to this day. They could do anything you want, they could provide special jetting, they could provide special finishes. They could rebuild your carburetor if send it back to the factory in Wisconsin. A great company, they know performance, and they know Shovelheads. They've also developed over the years stroker kits, big bore pistons, their own cylinders. Now they even have their own complete motors, Shovelhead motors.
They utilize a little bit of later model technology and have a little different look for the rocker boxes, they have internal oil line and other items like that that actually dress the motor up and made them a little bit more oil-tight and reliable. Great company to work for. If you want power from a Shovelhead, you got to have one of these or a derivative of one of these. We'll get into that more when we start fooling around with a running Shovelhead which we have out in the park and I will bring in shortly.
We're going to start the Shovelhead service. Shovelhead service is simple. We're going to pop the plugs out so we can adjust the valves, adjust the timing, do the rear chain. It's got a front belt drive. We're going to change the oil, but everything starts with the plugs. The first thing you want to do before you pull the plugs out you're going to take some compressed air and blow around the base of the plugs so that any dirt that may have been captured there is sent away so it doesn't fall into the plug holes when you pull the plugs. The plug wires come off with a little twist, leave them hanged. This is a '68, this is Jeff Lakey's Shovelhead, he just got up and running a couple of weeks ago.
He's got the short-reach plugs that were '74 and earlier back to '66. In '75 we went to a three-quarter inch reach plug. Make sure you put the right plugs back in that you took out. He's running a little rich. While we're over here, we're actually going to take the footpeg off and the primary cover off. That way we can get into the belt drive, check the tension of the belt drive and check the timing. When Jeff built the bike, he rotated the engine around to the time and markers where it should be in the middle of the hole and put a little mark on the belt drive. That way you can check over the light without getting all oily.
These custom motorcycle footpegs that Jeff put on are held in with a three eight bolt that was drilled and tapped into the end of the footpeg before it was bent and chromed. Jeff is quite the fabricator. There you see how he drilled and tapped it using a stock three eight bolt. Primary sealing case, placed with these straight head screws. With all the primary cover screws off we can pull the primary cover off, set it over here out of the way. You'll notice that Jeff has employed a inch and three-quarter inch wide belt drive with a Rivera pro clutch that has self-captured bearings. You may notice here on the front pulley he has made a yellow mark. That's to assist in timing.
What he does, he rotates the engine around, got the timing mark where it should've been, and put this little yellow mark so he can time the engine without pulling the timer plug out with the timing light and getting covered in oil. This is nice and clean, easy to do. While we're on this side we're going to jack up the rear so we can adjust the rear chain. Again we have a modified car jack from a Toyota. We just flattened out the top, put it on a piece of wood, slide it under the middle of the frame. I think we paid three dollars at the junkyard for this jack and we've had it for years. Works fine. Just get it up high enough so the rear wheel rotates.
Jeff's custom bike does not have an oil filter so oil changes are a regular occurrence. Keeping clean oil in there is a lifeblood of the engine. We're going to drain the horseshoe oil tank, it's got a drain plug right here at the back corner, the lowest part of the oil tank. Got an old pan underneath, hopefully, catches it all. Also while we're here we're going to drain the transmission. The transmission drain plug is located underneath. There's an outpoured mouth right under the kicker cover, what they call a fifth mount. Just inside that is a drain plug.
There's the drain plug. This is magnetic, you'll see it's got a little bit of metal here, not much. That's usually par for these things especially if they've been broken in, or I mean been brand new and then been broken in. You always get a little bit of led metal shavings, not much. I don't see anything here in the oil tank which is good. Get up a couple of minutes and put it back together, we got fresh oil here for the tank. We have some fresh oil over here for the transmission. The transmission drain plugs have a brass washer on them with a little shoulder so when you get close to having a drain plug snug, you want to go in there and visually check that your brass washer is seated against the case.
Okay, what we're going to do now is pour the correct amount back in and we're all ready to move on to the next phase. Oil fill cap has a built-in dipstick, it tells you what your oil level is. Since it's still warm here in California, we're going to use 60 weight oil. When it gets down to the first frost, rule of thumb is you would drop to 50 weight oil, it's thinner, easier on the motor, well it takes less time to warm up to the operating temperature.
In the summertime, you want the thickness of the 60 weight to protect the engine, helps to keep it cool. Transmission takes not quite a quart of oil, so you got to sneak up on it, not like that. There's no real scientific method of exactly how much oil to put in the transmission. The oil will gather here in the kicker cover and there's a port that goes into the main transmission case down in this region inside, so you pour oil in here let it soak, go over into the main case and then keep adding oil until you take your little finger stick it in here right to the first joint and go like that.
When your tip of your finger is covered with oil, that's where you want to be. Later model four-speed transmission kicker covers, will have a little pipe plug about here, you would take the pipe plug out and that's where your oil level would be, you fill it up so it just starts to run out, put the plug in, put your cap in and you're ready to go. They weren't so scientific back when this transmission was built.
That one's done, this horseshoe old tank usually holds three quarts of oil if you're starting from fresh with nothing, I mean the motors happen to run, you put three quarts oil and remove your vent, I mean return line from the pump which is this one here and you would pump any oil back into a clean container since this is the first oil change on this new motor so we've already done the one quart when we started it up the first time and when we drain the oil there we didn't see any signs of any metallic particles or anything so we're good to go.
While we're here, you'll see three oil lines, the bottom line feeding the pump is from the tank to the pump, this line here from the middle of the pump back to the oil tank as it returned and this line here coming off the back of your cam chest, is your vent line, does the same thing. Oil returns to the camp chest and any air that's being pumped from the piston is coming down, returns back to the oil tank so there's no venting to the atmosphere.
There is however a small fitting down on a lower part of the crankcase for any excess air that would need to get vented usually at high speed and I mean high speed. I mean it's like 5,000 RPMs which these things don't live at that often. Another one in, one more, first joint, plenty of oil, we're good to go. We're waiting for the oil to fill the tank, we can focus on the old pump here. This is an S&S pump, remanufactured by S&S motor company for various models of Harley Davidson.
I believe there are seven or eight different oil pumps over the years of Shovelheads, this one is nice and smooth, it'ss chrome, it doesn't have exposed fasteners like some of the early Harley pumps do and they have one or two pumps that will fit the whole range of Shovelhead motors. You have to make a couple of internal modifications but this is what they call a gear pump, inside this housing here there're a set of gears on the inside that pressurize the oiling system. There's another set of gears on the outside, they're called scavenge gears. What they do is they scavenge the oil that's run through the motor and pump it back to the tank to be cooled to make another return trip.
Later model heroics like the late-model Sportsters and some of the later model big twins like the twin-cam have a Dorota pump, where a Dorota pump is a gear that drives inside of a toothed circle as the elliptical action of the circle moves around, it actually squeezes the oil between the teeth forcing it either into the engine or back to the oil tank, but that's not until like 2000 later models.
For everybody's money nowadays S&S pumps are the way to fly, they look good and they work perfectly. Takes a few minutes to set them upright and after that you forget them. Okay I think we're done with the oil change, the only thing left is to clean up our mess and I'll move on, when we get it down off the lift what we'll do is we're going to get it started. We check it for leaks, make sure our transmission drain bolt, our old tank drain bolt are in tight.
Jeff, when he built this bike, has used to crimp on oil line clamps, most of the time you'll see worm drive clamps like on the fuel line where you take the screwdriver and you tighten the clamp to make it grip the oil line to the fitting but while you're still here, we'd like to go along and just take this line and see if it'll twist which these won't. If they twist, that means they're not perfectly tight. You can always tighten a worm drive clamp up with the crimped towel, you would have to replace a crimp style clamp but since this is a brand new, all brand new hoses there's no cracking, no dry rot, they're nice even arches so the oil flow is nice and smooth.
You won't see anything that's actually actually crimped or where it's turned so tight that it actually collapses the inside passage where the oil would go. You don't want to keep it close to the exhaust pipe, here Jeff has the steel lines that come down behind the pipe, the exhaust pipe and the oil lines actually fit to the hard lines there, same with the feed line, then you can have a nice gentle arc and you don't have to worry about the rubber being burnt by the exhaust which will burn right through allowing your oil to go all over the place not where it's supposed to be and if you don't catch it in time will ruin your engine which makes for a bad day. Okay, we're going to clean our mess up and move on to the next.
All right, the next segment of the service for the Shovelhead would be to adjust the primary and rear-drive chains. Jeff is running a belt as you can see for the primary, you would want to check that it's got good solid tension which this does. You can twist it a little bit, you can notice look along the edge here to see if it's framed. It's usually out of alignment. You want a belt to run straight and true which usually means there's a slight gap here at the clutch drum and another slight gap at the flange, at the front pulley.
This is good, there is no excess, just a little bit of rubber residue which is perfect. That's fine, we're not going to touch that. Back here on the rear chain which usually stretches. This is a brand new chain. It stretches two or three times the first 500 miles. You notice that this has a little bit too much play in it. What we're going to do is move the rear wheel backward taking some of the slop out. Before we do that, you'll notice that it has mechanical rear brakes. This is all mechanical linkage, so if we move the rear wheel back, we're going to actually pull the brake rod with it and lock the brakes up. The first thing we'll do is undo the brake linkage.
It's usually held in place with a clevis pin and a cotter pin, but Jeff has selected to use chrome nut and bolt which we just pop off real quick. Let the brake rod just hang down. Now, we can move the back wheel rear would unobstructed. Each side of the frame has a rear-wheel adjusting bolt and nut. The adjusting bolt will push on the axle sleeve moving the rear wheel back. First off, as you undo the lock nut, just give it a couple of turns. We'll reach around here and do the same.
Then we're going to loosen the axle nut which is the small one on the very end of the axle itself, just ever so slightly because a lot of times when bikes like this are built, the frames are sprung a little bit when you make the wheel spacers to fit and you pull the frame in, it'll actually spring. We have the axle nut loose. Now, we have to loosen this big nut which that is is the backing plate lock nut. You hold the backing plate tight against the frame because there's an anchor here and that's what your brake shoes work against when they grow to grab the drum when the brakes are applied.
It's all you need to do. Slack that off a little bit. Okay. Now, we want to rotate the wheel, moving the chain until we find the tightest spot. Boy, this thing is really loose. Right there is probably the tightest. What we'll do is move it back a little bit and check it again. You notice that the chain adjusting bolts are hex head. We looked at the sprocket. The sprocket is properly aligned. The sprocket is in between the side things of the chain. We know the rear wheel is already aligned. What we'll do is we'll count the number of flats on the adjusting bolt then we turn it back.
We'll start off with just two. one, two. Same for the other side, one, two. We'll come up here and check our adjustment. Now, look see I tightened up really nice with just two flats but we'll run it around and check it again. Okay, we can get away with one more flat I bet. One. Okay. Right there is our tight spot. You can see it has about a half-inch, 5/8 of an inch up in down plate midway between the two sprockets. That's perfect. What we're going to do just tighten down the back and plate nut first and make sure the backing plate's pulled all the way over and the anchor is in the frame slot.
Okay. Double-check. Okay. Now, the actual nut. Check again. Okay. We'll make sure the adjuster is in touch in the wheel. We're going to come back and tighten the lock nuts in place. The adjusting bolts have a 7/16 head on them. The lock nut is 9/16. All we have to do now is hook up the break. What we're going to do is without adjustment, we're going to stick the bolt back in the arm and our Able System, Mr. White, just going to hit the brake pedal for us. Mr. White? Okay, let go. It's actually pretty good. We only moved it a couple of flats back, so we're going to live with that.
We'll then put this nut lock on the other side and snug it back up and we'll be done with the chain adjustment. One more time, hit it, let go, perfect. While we have the bike raised like this, the chain is perfectly adjusted. We're going to lubricate the chain. There's a special chain spray, chain wax, in this case. What you want to do is there's four links to the chain, the two inside links, and two outside links. You want to get your chain spray right between those link plates on either side.
That way the chain lubricant will force its way and pass the plates into the rollers and that's where the links have to be lubricated because the chain rolls around each of those plates turn in succession as it goes around the sprocket. This could be a mess, so we'd like to have a rag that we can wipe the excess off. We're going to spray this. Rotate. It really helps when you do this when the chain is real warm like say just came back in from a ride you get the rear wheel up off the ground and spray your chain lubricant while the chain is hot.
Because you know that when metal gets hot, it expands a little bit.
Even if it's only microscopic a couple of thousands, it allows you more room to get the lubricant where it belongs inside the roller pins. We've lubricated the whole chain. Now, what we're going to do is wipe off the excess because no lubricant is going to do any good on the outside of the links. We'll just hold a rag loosely on the outside like this and gently rotate the wheel. You can see that we got a little bit of dirt and some lubricant. Do it a couple of times and we're done.
In the old days, a hundred years ago or so, when people were building custom choppers and they took stuff off, they didn't need a rear chain guard. You go to a bar and here's a guy and you could tell exactly what kind of bike he rode by where the grease stripe was on the back of his t-shirt. If the grease stripe was on the left side of his motorcycle t-shirt, he rode a big twin because the chain drive is on the left side. If he had a grease mark up and down the right side of his t-shirt, he rode a Sportster because the chain drive on Sportster is on the right side.
I like big twins. Now, we've just completed adjusting and lubricating our rear chain on a rigid mounted chopper. There's no suspension. You see the frame is rigid. That means the wheel will not change in relationship to the transmission. When the swing arm motorcycle hover where the swingarm pivots here, behind the transmission, the wheel will go up and down. It actually changes the distance between the rear axle and the transmission. The adjustment channel in swing arm bikes is a little bit trickier than on a rigid. These are easy. On a swing arm, you want to loosen up your axle. Get it loosened up. Loosen up your adjusters. Get them ready to go. You want to check and find your tightest point like we did here on a rigid mount. Then, if say, your buddy's bike, he weighs 150 lbs, you'd like to have him sit on the bike, that collapse the suspension to where it's going to ride all the time.
If you check your tension then at the tighter spot with him sitting on it and adjust it to that point, rotate the wheel or raise the bike back up. Rotate the wheel, check it again, get the tightest spot, and you're good to go. You always adjust at the tightest spot with the guy sitting on the bike because that's where it's going to go down the road. When you raise the bike up, the rear wheel will fall down a little bit, and it'll change the arc. You adjust there at the tightest spot. One he sits on it, it'll loosen up. You always want to have the rider on the vehicle when you do the adjustment.
It takes a little longer. I've done it by myself where I've got this high spot. Let the bike down onto the ground. Either lay across the seat and do it upside down. It's not that tough, but it always helps to have your friend there with you. Alignment on a swing arm bike is just as critical as alignment on a rigid frame bike. You want the sprockets to be in perfect alignment. The way to do that is as you spin the rear wheel in the direction of travel, of look and make sure that the side plates of the sprocket are centered over the socket itself equal distance from the side plates in on each side.
You noticed that we've said many times that you tighten, adjust the chain to the tightest point. The reason it's the tightest point because the chain will not stretch equally. Sometimes when the sprockets are a little bit worn, you just want to throw a new chain on. Your sprockets are not perfectly round, not grabbing the chain perfect. They're elliptical to a certain point. That's why you will always have a tightest spot.
It's which one. If they get to a point where the tightest spot only absorbs maybe an inch or two and you get around to the really loose spot, and the chain is actually flopping around hitting components, it's time for a new chain. While you're at it, you want to look at the sprockets and make sure that the sprockets are not going to chew up a new chain because they're hooked. If you look in here close, you'll notice that the sprocket teeth look like little pyramids. They're actually curved a little bit. If they should hook or move the wear surface one way or the other, it's time for a new sprocket.
On a drum brake bike, such as this one, you have to de-rivet the sprocket from the drum, put a new sprocket on and stake it with rivets. There's no moving it around because there's a shoulder that the sprocket goes onto and stays there. If you have to move stuff around or you're building a custom application, you may have to modify your spacers to get your chain sprocket in perfect alignment.
The wheel alignment goes right along with the chain alignment unless you're making something very custom, you would want to get your front-wheel tires in alignment, and then move your chain sprocket until it aligns perfectly with your transmission sprocket. If there's a distance to be made up, that's where you make your distance up. You don't want to fool around with wheel alignment or chain alignment because you start wearing components out way before their time is due. The last item on chain maintenance is after you got everything adjusted, you want to look at your master link clip.
The master link clip is the weakest spot on your chain. You want the clip to be solidly installed and you can check and make sure it is it's clipped into a little groove on the master link itself. The clip itself has an opening. You want the opening away from the direction of travel. By if some far-fetched reason you run over something, it will not run and push the clip off making you lose your master link. This one is perfectly installed here with the direction of travel away from the opening. It's something to be just to check, it never really goes bad unless you've installed the wrong master link or the wrong type of clip on that.
Always when you adjust your chain you always inspect it to make sure it's perfectly seated and it's not going to give you any troubles in the future. There's no master link, no drive chain, no movement. It's embarrassing.
Next thing we'll do is check the valve lash. To do that, we're going to remove the clips for the pushrods. Do the front ones first. Pushrods telescope up like this so you can see the adjusters. On these shovelheads, the actual adjustment is in the pushrod itself not in the lifter. This model had came with hydraulic lifters where hydraulic oil will take up the valve lash. This has a solid lifter conversion kit in it from S&S. What we'll do is we'll adjust it down to zero up and downplay, and then just get the feel of how tight that lifter, the push rod turns in the lifter.
Let me get my little assembly of hooks. This was made for us by a friend. It has dual hooks on the bottom and one hook on the top. This way you can hook both pushrod tubes and hold them up at the same time so you can adjust both valves in this cylinder. The hooks are rubber-coated or plastic-coated so you don't damage the chrome. Now what we do is you adjust the pushrods at their lowest spot. We're going to run the motor around and we'll watch the front exhaust because that's easiest to see for you. Here you can see the lifter going up.
Lifter's going down. As it goes down, rotate it there. You can see the pushrod turning. It feels good but it feels like it's just a little bit loose. The shell had been aluminum cases, aluminum heads. It grows in a different rate when it heats up. It's always nice to have the pushrods just so you can barely turn them up between your finger and your thumb. This goes away pretty easy, so we're going to just give it a little bit of oomph. You'll notice that the adjuster is at the bottom. This is the adjuster lock nut, and the top hex piece is pushed up into the pushrod.
That's the threaded part. We lock the lock nut against the pushrod, everything stays in place. What we want to do is elongate that pushrod just a little bit. We're going to hold the adjuster and just give the pushrod a little thump. That was a little bit too much but it's no problem. There's a fair amount more resistance. That's what we like. When you lock the lock nut, we go a little bit past where we'd want to go. It's a little bit tighter that we'd like. We put the wrench on a push rod and a wrench on a lock nut and pull them together like that.
When we get back, it'd be nice. This is just where we want it. We don't know if we're in the perfect space. What we do is we're going to run the engine around again checking the pushrod with various rotations. There goes up. You can't turn the pushrod at all. We're going to bring it down. As it comes down, we start trying to turn. Up right there. See it loosened up a little bit in that one spot. We go back and readjust it because that's now the loosest spot in the rotation of the cam. There. That's nice. One done. We're going to move to the intake pushrod front cylinder.
Here it's up, comes down, start check. Right there and that feels perfect. We'll check it everywhere, that one's good. I don't have to touch that one. Okay, we will just move on to the rear and do the exact same procedure. When we're done with that, we'll take our screwdriver and you want to make sure your lower pushrod tube-- it wouldn't hurt to wipe these things off. You can see how when they're facing into the engine it's hard to get in and wipe them off, they get a little dirty.
You want them to fit down inside this little pocket of the tappet block. There's a little cork gasket down there that seals the bottom. You want to raise the upper portion so it sits against the cork gasket in the rocker box. There's a little recess up there, you want to make sure it all inside there nice, it's nice there. Take your top pushrod tube clip, give it a little wipe down and that goes into-- you insert it up beneath the rocker box, take your screwdriver and just pry it up and push in, just like that. One more. Now, look at the chrome on that. Ok, that's sitting down in there, nice and tight up there and there you go.
Repeat the same procedure for the back and you're good to go. Before we leave the valves like I said earlier, this motor came with hydraulic lifters. We replaced it with solid lifters kit. When you have hydraulic lifters, you adjust the pushrod in the same matter get the lifter to the very lowest position, the heel of the cam and then you wouldn't shorten the pushrod until there's some up and down shape, where the pushrod would go up and down maybe sixteenth of an inch. You would then elongate the pushrod so that there's no up and downplay. You would read the package where you got your pushrods or your lifters and they would be either fine thread or coarse thread.
Each model will designate times you elongate your pushrod to get the proper setting for hydraulic lifters. You would then elongate it four times, three times, however many and lock everything in nice and tight, but you'd let the engine seat, you wouldn't rotate it for a while because what you're doing is as you shorten the pushrod, the oil in the lifter expands. As you elongate the pushrod, what in fact you're doing is opening the valve up here in the head. As you open the valve, it's got to sit for a minute before the oil bleeds back out of the lifter, allowing the valve to close.
Then once
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