This is not intended to take the place of the instructions in your factory manual. But. The manual is a little grey in some areas and downright confusing in others. Following the procedures in the manual has you jumping from section to section and back again. Plus, I found a few little shortcuts along the way.

Allow yourself several hours if you've never attempted this before. Take your time and always remember the axiom "Try before you pry." You are working with plastic and aluminium bits here that are easily damaged and expensive to replace.

Start by removing the A, B, C and D dash panels. Then remove both side cowlings, including the front bottom triangle. I will assume that if you've owned the bike long enough to get to this stage of maintenance then you've had these bits off before. If not, see and your manual.

Now, here comes the first shortcut. The manual also says to remove the windshield, windshield mounts and front cowling. This is not really necessary. The only reason to remove it is to gain access to the radiator cap, but with the side cowlings removed, the front cowling can be gently sprung to one side enough to clear the cap.

With the plastic out of the way, it's time to drain the coolant. It's not really necessary to drain the reservoir tank unless you are using this opportunity to change the coolant.

The drain plug is the hex-headed bolt among the collection of Allen bolts securing the water pump cover on the lower right side of the bike. Only a few dribbles came out until I loosened the radiator cap. With the suction broken, a stream of coolant 2 feet long overshot the 12" pan I had placed below the drain. In retrospect, it might be better to remove the rad cap first...

Raise or remove the fuel tank. I like to raise it and secure it with a ratchet strap to the rear carrier. In this case, I released the fuel pump and sender wires to get it up a little further. Again, I assume you've done this before too. If not, see

Release the t-bar frame brace by removing the A.I.R. valve mounting bolt and the 3 larger bolts securing it to the frame (green arrows). Slide rearwards out from under the A.I.R. hoses. Release the 5 A.I.R. hose clamps indicated by the red arrows. These are a pinch type clamp and for  some strange reason, Yamaha chose to locate the tabs on the underside of the hoses.

Follow the wire from the A.I.R. solenoid to the connector and release it by locating the tab and squeezing it while gently pulling the connector halves apart. The connector is typical of all you will remove today. They are all slightly different and keyed to fit one way only, so there is no worry of incorrect reassembly.

Now at this point Yamaha says to remove the thermostat housing (green circle). I found that was not really necessary and just removed the coolant pipe. It's retained by 4 bolts (red arrows). Two are Allen head, located down in the recesses where the pipes enter the engine, and two are Torx head, securing it to the thermostat housing.

Of course, what the manual fails to explain is that those recesses are dirt traps and you won't be able to find the bolt heads until you remove 40,000kms worth of accumulated debris. Even if you do find the bolt, DON'T SKIP THIS STEP. Any sand left in those recesses will be knocked directly into the valve train when you remove the cover, and I assure you that would be a Bad Thing.

ShopVac offers a nifty little accessory kit they market for cleaning keyboards. It consists of an adapter to fit the standard 1 1/2" vacuum cleaner wand and a selection of tiny wands, brushes and crevice tool that's just perfect for this application.

Or you can stay with the time-honoured mechanic's tradition of blasting the dirt directly into your eyes with compressed air and a small diameter blower nozzle.

Could you only find one bolt to the thermostat housing? That's because the other one is hidden underneath the pipe, where the pipe enters the housing. (red circle, with Torx bit in place.) Don't forget to unclip the wiring connector at the end of the pipe too (green circle).

Next it's time to remove the 8 cover bolts (red arrows). It will be helpful to loosen the wire clamp bolt (green circle) and retract the wire a bit so you can get at the right hand exhaust side bolt. Now is a good time for one last vacuuming to get any dirt that was knocked loose getting to this point.

Rotate the two throttle cables rearwards. This will provide just enough clearance to lift the cover and remove it to the right and back. Be gentle -- you don't want to damage the rubber gasket that will come with the cover.

Remove the timing cover on the right hand side of the engine. Note the two holes marked by red arrows. The bolts that were in those holes are longer than the others. Remember that on reassembly. Also, take note of the location and orientation of the hose retainer to the rear of the cover and the two wire retainers on the front edge (not shown)

This will allow you to rotate the engine with a wrench. Always rotate the engine clockwise as viewed from the bolt. Two reasons: first, that way you don't inadvertently loosen the bolt and second, some pumps can be damaged if rotated backwards. The Yamaha FJR1300 has two pumps. Why risk it?

Ok, now finally we're doing what we came for. Rotate the engine so the cam lobes are 180 degrees from the lifter surface. Slide a feeler gauge between the lifter and the camshaft.

The intake valves should have a clearance of at least 0.15mm and no more than 0.22mm. For those of you with SAE feeler gauges, round those to 0.006" minimum and 0.008" maximum.

Exhaust valves get hotter, expand more, and so they need more clearance when cold. 0.18 to 0.25mm. (~0.007" to 0.010")

Keep track of what you've measured and what you haven't. Each time you rotate the engine, you can measure one set of intake valves and one set of exhaust valves (from a different cylinder). I find it easiest to start with #1 intake and work my way across to #4, but whatever system works for you... First attempt to insert the minimum thickness feeler gauge. It should slide in with some slight drag.

If it doesn't want to go in, then the clearance is too small. Keep trying smaller thicknesses until you find the right one. Write it down! You will need to know that later. Make sure you identify which valve it is too -- you may well have several to change.

If it slides in loosely, then try the maximum thickness feeler gauge. If it won't go in, or if it goes in with a slight drag, then you are fine, carry on to the next valve. If it goes in loosely then keep trying bigger ones until you find the correct size. Again, write it down, you will need that number later.

If all your valves were within the specified ranges, then congratulations, you are done. Count yourself lucky, skip this next bit and go get a coffee. Meet up with the rest of us again at reassembly.

If, like me, you have one or more out of range, then you must continue. Step 1 is to position the camshafts ready for removal. Rotate the engine so the marks on the timing plate (red circles) align with the joint between the crankcase halves (green arrows).

Check that the mark on the right hand end of the camshaft aligns with the arrow on the cap. If not, then rotate the engine 360 degrees, so that the marks on the timing rotor align again. Positioning the camshafts like this will ease re-assembly.

Step 2 is to back off the spring in the camchain adjuster. Looking down the right rear of the engine, in line with the camchain, you will see the adjuster and it's plug poking out between the engine and the frame. May the gods forever curse the engineer who decided this was a good idea.

You can barely get a 10mm wrench in there to loosen it. Using two hands, you can just get your finger tips on it from above and below to remove it. And located directly behind it is a hole in the hollow frame large enough to swallow it. Do not ask me how I know this. Let's just say it's a good thing the plug is ferrous and can be retrieved with a magnetic probe. Do yourself a favour and cover the hole in the frame with a strip of duct tape when removing or installing this plug. Oh yes, don't lose the metal gasket washer either...

Ok, with the plug safely out of the way, pull the rubber plug from the outside of the frame to expose the slotted hole (green arrow) use a longish straight screwdriver through the frame and into the slack adjuster (red line shows path of screwdriver). Rotate clockwise to retract the spring. Wind until it stops and then give it just a little extra twist to "lock" the spring in place. Don't force anything -- just use enough pressure so the screwdriver no longer wants to unwind in your hand.

Now, the manual says you are to attach a piece of wire to the chain, remove all caps and remove both camshafts. I disagree. I found I could lift them one at a time and set them gently to one side, easily leaving enough room to access the lifters while leaving the sprockets engaged on the chain. That saves a lot of fiddling later, I assure you. At least one set of lobes is against spring tension at all times, so loosen all the caps a little bit at a time, so that they come up evenly. Take care to keep the caps in order and direction as you remove them. They are labelled with arrows towards the camchain and "I1" I2" or "E1" "E2" etc. if you mix them up. "I" of course refers to Intake shaft, "E" to Exhaust and "1" is the leftmost. Tuck a clean rag into the camchain tunnel to prevent any wayward pads from taking refuge in there. That too would qualify as a Bad Thing.

Once the shaft is out of the way, you can lift out the lifter (red circle), exposing the top of the valve (green circle) and possibly the pad. If the pad isn't sitting there in front of you, then it's stuck to the underside of the lifter by the oil film, waiting only for a chance to jump down the camchain tunnel.

Ok, the pads are marked by size. This pad is marked 188, meaning it's 1.88mm thick. Oddly enough, while Yamaha chose to install such sizes at the factory, the ones they supply to the field only come in 0.05mm increments. So, anything ending in a 8 gets rounded up, and anything ending in 2 gets rounded down to 0. This one is to be considered a 190 for the purposes of calculation.

Now here's the part where you need that measured clearance you wrote down before. Look up the original clearance along the left side, the original shim size along the top, and find where they meet. That's the shim size you need. This chart is for Intake valves only.

And this one covers Exhaust valves.

Now, before those of you with ISO feeler gauges go into shock, remember that the shims come in 0.05mm increments. That's about 0.002". So, for every 0.002" that your shim differs from acceptable, go up/down 1 size shim. An example:

Let's say the intake valve clearance was only 0.005". A 188 shim was installed originally. We round that up to 190. We need a clearance between 0.006" and 0.008". One shim size thinner would increase our clearance to 0.007". So we need a 185.

One last note: valve shims are re-usable. If you have a 185 elsewhere that must be changed, you can use it in this spot. Apply a thin smear of moly grease to the pad before installing it. Put the numbers up, towards the lifter. The idea is that the numbers will still be there next time you go through this...

Wipe everything down with a clean, lint free rag or shop towel. Then give it all a good bath in lubricant -- moly based oil or even gear lube -- before reassembly.

Double check your alignment marks. Make sure that the dot on the camshaft still lines up close to the arrow on the cap while the rotor marks align with the case joint. If the camchain jumped a tooth on the sprocket your engine will not run right and may even be damaged by a piston hitting a valve!

Tighten each cap a little bit in turn, so that all caps evenly draw the camshaft down against the spring tension. Use a torque wrench to tighten to a final value of 10 Nm (88 inch-lbs). Repeat for valves on the other camshaft if necessary.

When you are confident that all valves are done, the camshafts are correctly synchronized to the rotor and the caps are properly torqued, release the camchain adjuster with your longish screwdriver. Rotate the engine two full turns and check the alignment marks one last time.


Ok, those of you who lucked out and required no adjustments can rejoin us now.

Re-assembly is a fairly straightforward reverse of the process. Yamaha recommends using some sealant on the cover gasket, but on examination I didn't feel that was necessary yet. The problem with sealants is twofold: they make a mess going on, and they have to be cleaned off next time. Later on in the gasket's life I'm sure it will need a sealant but not now. Your gasket: your call.

One thing to be careful of during re-installation of the cover are these half-moon projections. First, they stick out so they are easily damaged. Second, they're rubber mounted so they're easily knocked out of position. If they don't sit in the casting properly they will leak -- sealant or no sealant. And because the head sits between the frame rails, it's hard to tell if they are properly positioned. I located the cover in place, lifted the rear, peaked underneath to see they were pointed in the right direction, and carefully lowered the cover into place. No problem.

Don't forget, rotate those throttle cables backwards before trying to install the cover!

Use new o-rings on the coolant pipe. Lubricate with a suitable product such as Parker's Super-O. Don't use engine oil, this is your cooling system. If you don't have anything else, use a bit of liquid dishsoap, but be forewarned: it will dry up and make the o-ring difficult to remove next time.

The two that enter the engine are a fairly common size -- R-13. The one to the thermostat was not in any of my standard mechanic's o-ring collections, but I did find it in a set of plumbing o-rings for faucets -- # 35776. Also available from Yamaha, I'm sure.

Did I mention how difficult it was to remove this sucker? Just wait'll you try installing it! Ok, maybe you ignored my advice, got lucky and removed it without covering the frame hole but trust me: nobody gets that lucky twice. Get the duct tape.

Before getting carried away fitting that rubber sheet back in place, (which will hide any leaks from view) temporarily install the A.I.R. hoses, reconnect the wires, etc. Refill the radiator and reservoir, install the cap, replace the cover over the timing rotor and fire up the engine. Let it run until hot -- ie: 4 bars and the fan kicks in -- checking for oil and coolant leaks. Shut it down and let it cool right off. It was time for a beer anyway, right? If you are sure there are no leaks, properly install the rubber sheet, A.I.R. hoses, etc. Top off the coolant reservoir as required before installing the plastic.

Next time, I think I'll try just removing this plug over the timing rotor bolt, instead of the whole cover. I'm confident in my ability to ensure the timing chain doesn't skip a link, and I now know the camshafts do not have to be completely removed. On the plus side, it takes an o-ring seal, not a gasket. On the down side, unless the cover is removed, you can't check the cam alignment for sure. Your bike, your choice.

Copyright © 2004, by Dwayne Verhey and H. Marc Lewis.
All rights reserved.