AIRHEAD VALVE ADJUSTMENT with Pics

OK, it's gonna be a long one, pic heavy, but here we go:

Airhead XJ valve adjustment: We're going to be working on my '83 XJ550 Seca. Since all air cooled XJs use the same procedure for adjusting the valve clearances, here it is:

First off, DISCONNECT the BATTERY. The easiest thing to do is disconnect the ground wire, wrap a shop towel around it and tuck it out of the way.

MAKE IT A HABIT TO DO THIS BEFORE DOING ANY "DISASSEMBLY" WORK ON THE BIKE. It will prevent possible disaster.

Remove fuel tank Be sure to disconnect BOTH lines from the petcock.

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Tie up the plug wires so they are out of our way for the duration, I used a piece of string because it was handy.

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Remove obstacles On the 550, the flasher relay has to be slid off its mount and got out of the way.

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Loosen the cover bolts completely, They won't want to come out, that's ok, just be sure they are fully unscrewed.

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And the outers, once again, completely loose but don't worry about lifting them out they may not want to come out.





Crack the cover loose I used my patented RickCoMatic carb rack pry tool (wooden hammer handle) pry firmly around it at various spots and it will pop.

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Lift cover up until you can see that it will clear the camchain



Slide the cover clear just be careful of the camchain tower




Remove the ignition cover Use an impact driver if the bolts are stuck




Rotate the crankshaft using a 19mm wrench. BE CAREFUL not to crash into the ignition pickup coils.
NOTES: Cams rotate the same direction as the crank. Rotate "forward" (Counterclockwise) whenever possible. There will be times when you HAVE to rotate the motor backwards. GO SLOWLY. On the 550s the starter engages and you drag it along for the ride.




Make yourself a chart, for #1, #2, #3, #4 cylinders, both intake and exhaust. I lay the chart out like the motor is laid out it just goes easier.

Rotate the crank (forward, CCW) so that each cam lobe in turn is pointed "skyward" away from its bucket at a 90 degree angle from the surface of the shim, and check the clearance between the heel of the cam lobe and the top of the shim.







Check the clearances on all the valves and record them on your chart.

Now it's time to read some shims.

For any that are OUT OF SPEC, first: Check the location of the NOTCH in the edge of the bucket. ROTATE the bucket (while the lobe is up) so that it is positioned toward the inside so that you can get your shim popping tool into it. Look closely at the exhaust valve (on the left) bucket in the pic below and you can see the notch.





Rotate the motor (still forward) so that the valve you want to check is FULLY OPEN (cam lobe CENTERED on its bucket.)

Place the "tool" in position, hold firmly against the cam lobe and bolt it down. It should sit "square."




Here's a fully open valve with the tool in place.




Now for the very important part: With the tool in place, rotate the motor (and cam) away from the tool until the lobe is sticking back up in the air again.
YOU MUST NOT ROTATE THE CAM TOWARD THE TOOL AT ALL. There is enough mechanical advantage here to CRACK THE HEAD. The cam must not push against the tool bad things will happen.
This is where you may have to turn the motor backwards.
Once the heel of the cam is over the bucket (and the tool successfully held the bucket down) you can stick a small NON MAGNETIC screwdriver in there and pop the shim up. IF the edge of the bucket/shim comes back UP beyond the edge of the head casting the tool "missed" and you'll have to do it again. It just takes practice and be sure the cam is EXACTLY centered on the bucket when you bolt in the tool and it will work every time.





Using a NON MAGNETIC TOOL* I prefer hemostats, pluck the shim out.



*Non magnetic tools are important as the shim and bucket are made of an easily magnetized alloy. If they become even weakly magnetized they will attract microscopic particles of metal and accelerate the wear on the cam and shims.



Read and record the number on the back of the shim, and put it back.





REPEAT ABOVE PROCESS FOR ALL OUT OF SPEC VALVES. If you're seriously anal like me, pull, read, and record them all so you have it for next time.

Keep in mind the valve train tightens not loosens as it wears on these bikes. It is rare to find a "loose" valve, they will either be good or tight, or VERY tight.

Using the valve shim replacement chart, determine what shims are needed based on the measured clearance and the currently installed shim.
Per chacal, all the XJs have the same valve clearance spec except the "X" models and the XJ1100.




When installing new shims, make sure they are WELL OILED with clean motor oil. I keep a small plastic tub of oil nearby and dip them just prior to installing. Once again, non-magnetic tools ONLY!!!

INSTALL SHIMS NUMBER SIDE DOWN.

Once all your new shims are installed, rotate the motor FORWARD (CCW) three or four revolutions and RE CHECK all the clearances again. We all make simple mathematical errors on occasion.

Once everything is in spec (and you recorded the shims you installed and the new clearances) it's time to button it back up.

Check your valve cover gasket thoroughly and if it's crispy anywhere, replace it. Take a look at the rubber gaskets on the bolts. You may have to smack them from the back to dislodge them from the cover. Here's why we replace the "donuts"



Look at the thickness of the area where indicated. You can see how the old "donuts" have compressed compared to the new ones.

Note the shoulders on the bolts. The bolts only tighten up to the shoulder and then STOP. The "donuts" are what actually push the cover down against the gasket. I recommend replacing the gasket and the donuts the first time you do this and then you won't have to for a few YEARS and it won't leak.

You will have to get medieval on the old donuts to get them off (I just cut them off) use a dab of silicone grease to pop the new ones on.

Valve cover prep: Here my assistant is applying 'decanted' High-Tack spray gasket sealer to the gasket groove with an old artist's brush. Once it dries, about 10 minutes, it becomes the stickiest stuff on the planet.




Then grease it up The gasket is glued in place so now it gets a good smear of silicone grease prior to reinstallation.




Reinstall the valve cover; remember the stop collars on the bolts so don't overtighten them, torque them to the proper spec which is only 7.2 ft-lb. It's hard to get a torque wrench on the inner ones, so tighten them until they stop and then just be sure they're good and snug.




If you used new donuts and a new gasket it WILL NOT leak.


If you want additional pictures of anything or need anything clarified please just let me know right away while I still have the bike apart. I can always snap more photos, just ask.

I hope this helps, I wish I'd had something similar my first time I only had the Clymer book at that time and it sucks as far as being able to see what they are talking about.

Cheers---Fitz

 

Fitz,
a masterful job, well done. this is probably next on my list to do. thanks again.

 

Fitz......exceptional. And a very nice watch, too.

P.S. the engine will become much easier to turn over with the wrench if you remove the spark plugs.

Also, the valve shim clearance are the same for all the XJ-series bikes except the XJ700-X (waterhead) models, and the XJ1100's:


Valve Clearances:
-always measured with engine at "room temperature":

550:
Intake: 0.11 - 0.15mm ( = 0.004 - 0.006")
Exhaust: 0.16 - 0.20mm (= 0.006 - 0.008")

650 all x. Turbo:
Intake: 0.11 - 0.15mm ( = 0.004 - 0.006")
Exhaust: 0.16 - 0.20mm (= 0.006 - 0.008")

650 Turbo:
Intake: 0.11 - 0.15mm ( = 0.004 - 0.006")
Exhaust: 0.16 - 0.20mm (= 0.006 - 0.008")

700 non-X:
Intake: 0.11 - 0.15mm ( = 0.004 - 0.006")
Exhaust: 0.16 - 0.20mm (= 0.006 - 0.008")

700-X:
Intake: 0.11 - 0.20mm (= 0.004" - 0.008")
Exhaust: 0.21 - 0.30mm (= 0.008 - 0.012")
NOTE: special tapered-point feeler gauges needed due to extremely cramped working environment on these bikes; also, the X-models use a unique valvetrain that uses "pads" rather than "shims" and basically takes all day to perform the check, and about as long if you have to replace any of the pads on the 20 total valves!

750 M/MM:
Intake: 0.11 - 0.15mm ( = 0.004 - 0.006")
Exhaust: 0.16 - 0.20mm (= 0.006 - 0.008")

750 Seca:
Intake: 0.11 - 0.15mm ( = 0.004 - 0.006")
Exhaust: 0.16 - 0.20mm (= 0.006 - 0.008")

900RK:
Intake: 0.11 - 0.15mm ( = 0.004 - 0.006")
Exhaust: 0.16 - 0.20mm (= 0.006 - 0.008")

1100:
Intake: 0.11 - 0.15mm ( = 0.004 - 0.006")
Exhaust: 0.21 - 0.25mm (= 0.008 - 0.010")

 

Fitz, what a beautiful job. That's the way the manuals should have them. But then nobody would have to ask any questions.

 

GREAT JOB Mr. FITZ!!!!!!! Thank you for share it.

 

True. However, a really smooth motor with the plugs out can actually "coast" a bit, forward or backward, in response to the pressure from the valves on the cams. Leaving the plugs in means the motor stays exactly where you put it and forces you to go slowly. On a 650 or 750 you probably need to pop out a plug or two.

I probably should have mentioned that the camera I used is a Canon SX110 IS, and it takes pictures at 3456 X 2592 (by default.) I then resized them to 1024 X 768 using Adobe Photoshop.

 

Great job, Fitz. Thanks!

 

Excellent. Much appreciated.

Thanks for the handy clearance chart Len, I'm printed it and stuck it in a plastic sleeve in my 'XJ' notebook (book containing secret information gathered over time from here).

 

Since chacal cleared up the clearance issue (did I make a funny?) I will edit the post to include the shim replacement chart as soon as Photobucket starts behaving itself again.

 

Great Job. Very informative. Was also wonding if anybody has done the same with a maxim x. I have an 1985 750 maxim x and was thinking about doing a valve clearance check, but like chacal mentioned, the valve train looks prety cramped. Was just looking for some advice or pics to help. Thanks

 

Shim chart added

 

Great thread Fitz !! Nominate for Sticky Status !
And to help out, links to the "zip-tie" thread,

http://xjbikes.com/Forums/viewtopic/t=4 ... c+tie.html

Home-made bucket holder tool thread,

http://www.xjbikes.com/Forums/viewtopic/t=1232.html

Chacal has the tool - HPC247 for $15.00

 

nice!! definitely sticky-worthy. thanks fitz

 

Thank you for your tme on this project. I just this afternoon took the valve cover off and had a look. Naturally my feeler gauges are at work. Oh well , next week. With your information and the great pics the job will be done much faster. I will be looking for a new gasket and rubber mounts, any suggestions as to where to get or order from.
Bike is a 1983 750k. Thanks

 

Planehue, I carry all the parts you'll need, just follow the link below in my sig line.......

 

thanks fitz! I was just about to search this topic when i saw your post great timing thanks again

 

Great write up! Had mine all recorded in a lil over an hr with this forum. 5 out of 8 too tight yikes. And a piece of 12 gauge elec wire worked great as a valve tool.

 

UPDATE: Got all the shims in; even the one that was "in spec" was right at the tight side so I dropped down a size on it too.

In case you're interested here's where we ended up:

Cyl: #1 #2 #3 #4
EX .18 .18 .17 .19 (spec is .16-.20mm)

IN .13 .12 .14 .12 (spec is .11-.15mm)

I recorded all the shims installed as well.
I'll be paying close attention to EX #3 and IN #2 and #4 next time around, but I feel MUCH better about this motor now.

 

Is there such a good write up for Maxim X?

 

Fitz, Can you explain the "feel" of the feeler gauge when you check your clearances.
I've always just adjusted till I could feel a slight drag on the gauge when you pull it back.
Thanks

 

A slight drag is just right. You shouldn't have to force it in or yank it out but it shouldn't fall thru either. When checking the valve clearances on my XJ's I do a "go-no-go" thing with the next bigger/smaller size to be sure.

It really helps with metric bikes to have a metric feeler gauge, not an american one with the oddball metric equivalents on it. I also have a metric tape measure and a metric caliper for the same convenience.

 

Where Does one find a metric feeler gauge, Sears????

 

I couldn't find one at Sears. I have one of these http://www.kd-tools.com/2274.htm I got it on-line I don't remember where (could even have been Sears' web store.)

 

I have them in stock!

 

Fitz, that photo journal was perfect. You could write manuals capable of turning a sales guy into an astronaut.

I'll be checking my valves as soon as possible. I'm stuck on the sofa for a couple of weeks after surgery.

 

Feeler Gauge .... I ordered one from My Snap On dude, was $9.98 goes from .05 to 1mm in .05 increments. Must be the cheapest thing I have ver ordered from him.

 

Quick update: I added "valve cover prep" photos (glueing and greasing the gasket) to the original post. You may notice the valve cover underwent a transformation in the process. Cheers---Fitz

 

Awesome guide Fitz! especially for those of us who haven't done this before. It really helps to see how easy it is before we jump in! AND to know what to expect!

<sticky vote>

 

Thanks. You got it easy, only 4 to do and a tad more room between the top of the motor and the rest of the bike. Enjoy!

 

Great Job with the pics!!! What did you do to get the valve cover looking that good?? I am heading home to check my valves. I am going to try the zip tie holder.

 

Now it says to change shims as needed. Where does one aquire these numbered shims?

 

And what is this "Tool" you are using in the pics? What is it doing exactly? Holing the lobe in place?

 

The tool holds the bucket down so you can remove the shim. Shims and the tool are available from our friend Chacal

 

The ever illustrious Chacal. What a guy. That'll be my next mechanical project. Sucks I'ma have to take check the clearances and then have to wait a week for the parts when I do it though

 

Unfortunately you have to check - pull the shims that are too tight to get the size then reinstall if you wan to ride. Order the shims then do it all over again.

Sometimes your local dealer might have them.

 

Just checked shims...
I used abouta an 8 inch piece of weed wacker string with almost half inch 90 degree kink on one end(was thicker and stronger then zippy tie)
With the the lobe fully pressing on the shim your going to check( you will see the vlave come down inside the spark plug hole)... stick the bent end of wacker string into the sparkplug hole
Spin the wacker string angle towards the valve.
Rotate engine CCW till you see the most clearence between the valve shim and the Cam lobe.
Tug on your wacker string. If it comes out you missed....try again. Some shims were pretty well stuck and useing a thin screwdriver you need to put some good levering on it.

 

Fitz, shouldn't the step below state 180 degrees and not 90 degrees?

As usual a brilliant instructional aid. We are lucky to have you on this forum.

Rotate the crank (forward, CCW) so that each cam lobe in turn is pointed "skyward" away from its bucket at a 90 degree angle and check the clearance between the heel of the cam lobe and the top of the shim.

 

I meant 90 degree angle to the (visible) surface of the shim; it would be 180 degrees from the centerline of the bucket but that might be more difficult to visualize. I was trying to explain that they shouldn't be STRAIGHT UP, as the buckets/valves are at an angle, that they should be straight up IN RELATION to the surface of the shim.

How about
"...each cam lobe in turn is pointed "skyward" away from the surface of its shim at a 90 degree angle and check..."

I'll go back and change it if you think it will be more concise that way, I'm always open to suggestions.

Technical writing is an art, I'm just an IT guy, but I did stay at a Holiday Inn...

 

Now I understand what you're saying. When I visualiaze it I think of the cam lobe pointing exactly opposite of the bucket, or 180 degrees away. Or in line with the valve stem, pointing away from the bucket.

Here's the bottom line. I seem to be the only person having difficulty understanding what you were saying so I don't think I'd change a single word. Again, thanks for a great write up.

I am so looking forward to working on this bike. I kind of ran into a snag this evening when I mentioned to the mama that I would be going to Harbor Feight to pick up one of those motorcycle lifts. We're buying another house and she seems to think I should hold onto the money for an emergency. She just doesn't get it! Too old, too fat, too grouchy to lay on the garage floor to work on a bike.

Maybe I'll let her see me suffer a bit!!!

 

Hmmmmm......that explains a lot!

 

Wonderful post bigfitz, I guess it would look alike internally for XJ700 (non X).? any idea !!

 

I have a '80 XJ650. The only gasket available is paper.

Will the gluing technique work on a paper gasket?

If not, are there other techniques I can use to re-use the current gakset (if not "crunchy") or the new one I just got from chacal?

I want to be able to ride my bike while I wait for the new shims to arrive.

Thanks.
Jim

 

littlegiant It's my understanding all the "airhead" XJs are the same; the only difference being some of the bigger bikes might have less room to work in there

AND the pre-YICS motors have different hold-down bolts and gasket, which brings us to...

minturn yes it will work fine on your paper gasket. I used the same technique on my clutch cover and ignition cover gaskets and they are perfectly reusable as long as you grease or oil the "release" side.

 

Okay, I am getting seriously grumpy here.

I have followed these directions to the letter, as well as some adaptive measures given by MjCarl elsewhere.

First I tried centering the lobe on top of the bucket and seating the tool, pushing the tool firmly against the cam. When I then rolled the motor forward to have the retaining tool hold down the lifter, the tool was completely ignored and the bucket came all the way up and there was no slack on the shim.

I followed MJCarl's advice to not have the Cam lobe centered on the bucket and roll it forward a bit. Still no contact. I held the thing in place and cranked the motor around and there was never any contact of anything with the tool, until the cam lobe came near, of course.

I blew well over four hours on this today and am more than a little cranky. It seems the retaining tool never makes contact with the lifter

 

QUESTION:
The numbers have smeared and are illegible on some of the shims that I have taken out. Is there a way to know what number the shims are without looking at the numbers on the back?

 

Mike; I too was ready to tear my hair out the first time I used the tool. Carl's directions are correct, the cam lobe has to be away from the tool and pushing the bucket down. I have better luck if the cam has almost pushed it down all the way; and then push the tool against the heel of the cam and ensure the tip of the tool is centered on the edge of the bucket.
(This is impossible to do except by guess and by golly since you cannot see the tip of the tool.)

I can tell you this: Once you DO get the hang of it, it works 19 times out of 20.

Motorduck: Measure them. You can get a cheap digital caliper for under $15 these days, and quite decent ones at that. Or take 'em to your corner auto repair shop and have them mic' them for you. A 260 shim is 2.6mm thick; a 245 is 2.45mm, etc.

If that's not possible, swap in one you CAN read, and measure that new gap and reshim accordingly.

 

thanks bigfitz.

 

I finally did get the knack of it Fitz. It sure would be nice if that damned tab was a mm or so longer. It is a *real* major PITA to get the shims out of the center buckets. You have no room to manuever and can only come at them from one direction. Damned near impossible. Having that bucket down another mm or two would make a heck of a lot of difference by adding that much more clearance.

 

getting the notch in the bucket so it ends up in exactly the most advantageous spot for popping the shim loose is part of the art as well; I still curse at myself when I've got the tool in place and the bucket is down but the notch moved so a do-over is in order...

I'm glad you got it finally.

 

Hear hear! We poor X owners have it hard enough. There is a thread here but not much detail. I pulled the tank, decorative pieces, horns, coils, and then the eight bolts on the head cover. Pull the ignition cover same as in Fitz's guide here. Using a narrow feeler gauge set from Chacal it was easy enough to measure the clearance. Apparently we have to pull the cams off the top to get the pads out - that's my next step.