The ’83 Ironhead is fun project bike, but like all AMF Harley-Davidson bikes, it’s a finicky bitch. Everything else with the project is coming together smoothly, but I just couldn’t get the clutch properly adjusted. I didn’t have a shop manual handy, so I Googled how to adjust the clutch on a 1983 Ironhead, and while there where a few promising results, there were an equal number of depressing ones (like “FUCK: Fucking ironhead clutch!!!!!!!” over on Chop Cult).

I tried a couple of the techniques suggested in various forums and blogs, but I didn’t have much success: I kept either adjusting it out so far that it would never engage, or adjusting everything back in so the clutch was constantly engaged. In either case, it didn’t matter if the clutch releases lever was in or out: I simply couldn’t find the middle ground.


I finally gave up on the Interwebs and got my hands on a ratty old copy of the Harley-Davidson Service Manual for XL/XR Models 1000cc 4-Speed 1979 to 1985 (Part No. 99484·85), hoping my luck would be better than the other would-be Ironhead gurus out there banging their heads on the bikes’ pitted chrome battery boxes and rusty peanut tanks.
Form the manual, the procedure for “Adjusting the Adjusting Clutch Release Mechanism” is as follows (referencing Figure 6-5 from the manual):
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Loosen clutch cable adjuster locknut (13) and turn adjuster (15) inward until there Is a large amount of free play at hand lever on handlebar.
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Remove access plug (1) from primary chain cover using ACCESS PLUG REMOVAL TOOL, Part No. HD-33186.
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Loosen adjusting screw locknut (3) using CLUTCH ADJUSTING NUT WRENCH, Part No. HD-94580-71, and turn screw (5) Inward until it becomes harder to turn (starts to release the clutch) and continue turning (2 more turns) to be sure clutch Is disengaged.
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Adjust all free play out of clutch cable by turning adjuster (15) outward. Do not put any tension on cable. With all slack In cable eliminated (no play at hand lever) tighten the coll adjuster locknut (13). This Is the correct cable adjustment.
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The clutch release adjustment should then be made with the clutch adjusting screw as follows. Back off the adjusting screw (5) until the clutch Is engaged (screw turns easier), then, turn screw Inward until the point where free play of adjusting screw has just been eliminated. From this point, turn the adjusting screw outward 1/8 to 1 1/4 turn to establish correct free play, and tighten locknut (3) while holding screw (5) stationary.
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See Figure 6-6. Check free play at clutch handlever. There should be 1/16 In. free play between handle and bracket. If Incorrect, readjust sleeve (15, Figure 6·5) and tighten locknut (13).


NOTE: If the clutch continues to slip under load or drag in released position, clutch springs may need adjusting or release mechanism may not be operating. See subsequent sections.
The subsequent sections sounded scary enough that I really, really wanted to make this work.
Unfortunately, the procedure in the manual proved as useful as all of the guides I found by stumbling around Google. Tinkering around, I came up with my own procedure, modestly named:
Curtis’ Mega-Awesome Ironhead Clutch Adjustment Technique Extraordinare
- Drink at least three beers.
- Tighten the adjustment cable all the way down using whatever wrench fits.
- Loosen the lock nut with the right sized socket. Don’t waste your money on CLUTCH ADJUSTING NUT WRENCH, Part No. HD-94580-71. You can even remove that damn lock nut, since it will just be in the way until you’re done.
- Loosen the adjusting screw using whatever low tech instrument you have on hand (such as a flat-head screwdriver or butter knife) until it ALMOST falls out. I don’t think you’re screwed if it does fall out, but it’s best not to find out.
- Pull the hand lever and notice how wrong that feels.
- Try rolling the bike with the hand lever pulled, and see how wrong that feels.
- Now put the bike in gear and try STEP 6 again, you moron.
- Drink three more beers.
- Loosen the cable adjustment all the way out (trying not to remove the damn thing).
- Tighten the adjusting screw all the way down. Tight. No, tighter.
- Pull the brake lever, and notice how bad that popping sound is. Don’t do that again.
- Drink another beer and hope you didn’t screw anything up.
- Tighten up that cable adjustment a little bit, so it doesn’t make that popping sound when you squeeze the clutch lever.
- Try rolling the bike, in gear, with the clutch lever pulled, noticing that you’re still all knackered up.
- Let go of the clutch lever and roll the bike around in gear, noticing you’re REALLY knackered now.
- Drink another beer and think about this.
- Unscrew the adjustment screw (not the cable adjustment, you drunk idiot!) until it is about to fall out.
- Now screw the adjustment screw back in until you feel it start to get tight.
- Put the lock nut back on, but don’t screw it down too tight.
- Get on the bike and roll it back in forth, pulling the clutch lever and then not pulling. Pay attention to how much play is in the lever, and how hard it is to roll the bike.
- Don’t drop the bike: you’ve had a lot of beer, and it will be a real bitch to pick it back up again while you’re drunk.
- If the bike is in gear, you aren’t pulling the clutch lever, and the bike rolls freely, you need to loosen the adjustment screw a few turns. Just do it a few turns at a time.
- If rolling the bike starts kicking the pistons over, GOOD!. Don’t mess with anything yet.
- Now, with the bike in gear, pull the clutch lever, and roll it. If the pistons start kicking over, you need to tighten the adjustment screw a few or several turns.
- If you’re starting to sober up, you may notice that, even if the pistons don’t roll over, the Ironhead still seems to resist rolling. When these bikes are cold, the clutch plates have a tendency to stick, so as long as you can roll it with a litter effort, but not turn the pistons, you’re in good shape.
- Don’t drink any more beer.
- Tighten the adjustment screw lock nut.
- Tighten the cable adjustment lock nut.
- Put the cover plug back on (we’re going to assume it fell off itself at some point, since I didn’t include a step to remove it). Use something with a eight inch edge. I used the fender struts from a 1983 Honda Shadow VT700C, which I cut off the frame when I was turning it into a bobber.
- Drink some coffee.
- Now go ride it, and see if that clutch is working.
Even after using my foolproof technique, I still didn’t seem to be getting the torque I was expecting when I test rode the Sporty. I suspected the clutch was slipping because of worn friction plates, or springs, or wouldn’t engage properly because of a worn ramp or some other annoying problem. I ordered the parts to rebuild the clutch per the dreaded “Subsequent Sections” in the repair manual, but something was still nagging me: if the clutch were worn out, how could it turn the piston when rolled, and not turned them when the clutch was pulled? It didn’t feel like it was slipping when under human power?
Was it something wrong with the transmission.
And right as I began drifting off to sleep, dozing but still slightly coherent, I had a flash of memory, of taking my 1977 Ironhead (my dear Imperial Entanglement) for quick ride around the block one morning shortly after I bought it. I had just filled it up with gas, when suddenly I started loosing power. It could still pull me, but my rear end (with the rest of me included that’s about 400 lbs of awesome), but it had lost it’s pep. My Sporty was no longer it’s Sporty self.
I went to sleep with that thought on my mind, but I didn’t make any connections until this afternoon, after firing up the ’83 Ironhead again and wondering what I was doing wrong. I thought back on the ’77 Ironhead and realized the sluggishness I felt with it was very close to the “slipping” I was feeling on the ’83. The power just wasn’t there, like it was only half a Harley.
It was only half a Harley.
I was only getting 500cc instead of 1000cc.
Sure enough, when I fired up the ’83 Sporty and put my hand behind the front exhaust, cool air was pumping out. The rear exhaust was nice and hot. I pulled the plugs and cleaned them (the front was caked with carbon deposits) and popped them back in. The front still pumped out cool air. I swapped plugs, and the problem followed the plug, pumping cool air out of the rear exhaust.
So here’s the new STEP ZERO in “Curtis’ Mega-Awesome Ironhead Clutch Adjustment Technique Extraordinare”:
CHECK YOUR EFFING SPARK PLUGS, YOU MORON!!!!!
I swapped the old plugs for some older (but known-good) plugs, and fired her up. Immediately, I knew I had back 1000cc of Ironhead awesomeness, and that ’83 Sportster zipped my big butt around the block like I was some elfin fairy waif. But in a badass, cool, elfin fairy waif kind of way.
And the clutch is in perfect adjustment.