CURRENT MILES
22,000 ish
It’s been one of those things in the back of my mind for so long. I know that my 2014 KTM 690 Enduro R has rocker arms that could go bad. Apparently it’s the lubrication of the roller that rides on the cam shafts. The bearing goes bad and when it does you have no more valve lift (no power) but also plenty of weird noises and of course there’s all that bonus metal and crud now floating around in your oil system. The easy fix is to upgrade to the new version of rocker arms and since you are in there… why not just replace the shafts as well, right?
Kyle has a 2015 and so I ordered arms and shafts and gaskets for both bikes. I verified that they were the same parts numbers and ordered everything we needed to do both bikes at the same time.
Of course we chose a 100+ degree day to do this. A little shade helped but it was still a sauna out there. In all fairness, we (mostly Kyle) worked when it was cooler in the morning on getting his BMW final drive back in the bike. I was also changing tires so those are the new ones sitting in the sun getting soft.
We did his bike first, and then mine. It’s pretty simple.
- Seat and side covers off.
- Airbox out (we both have Rottweilers so it was really easy).
- Next, clean away all the dirt and grime that could fall into your motor when you take the valve cover off.
- Make note of where the three vent hoses go.
- Pull out a spark plug or two.
- Pull out your plastic plug on the left side of the motor. It’s a 14 mm Allen. Don’t have one? You could use a 14 mm Bolt – stick the head into the hole and turn the bolt with vice grips. Don’t forget that there’s a rubber o-ring in the too.
- Now you are ready to get started.
My bike has 21,650 miles and since it was used when I bought it I wasn’t sure the rockers were ever done.
Spoiler alert – they were not.
In this we’re not only replacing the rocker arms, we’re also adjusting the valves.
Valve Specs are supposed to be between .07mm to .13mm for both the intake and exhaust. It’s easier to keep track of things by doing just the intake (or exhaust) side first. I had a note pad and made an X,Y axis. Top was the exhaust side, bottom was the Intake. Vertical was left and right as you were looking at down at the motor.
Pull off the valve cover. It’s pretty simple, just 4 bolts. With the bolts removed you’ll need to wiggle it out of the trellis frame a bit. This is why you just cleaned all the dirt from it, eh?
Now sitting on the left side of the motor you can stick a socket in and turn the motor over COUNTERCLOCKWISE. It’s still going to have some compression. You want to rotate the crank so that you see the intake valves open and close and then you’ll see the timing mark in the center of hole (below) and both rocker shaft will be accessible through there holes. I didn’t get the camera at the right angle but you can see all three holes here are lined up and if you look close you’ll see a little notch directly under that torx in the center.
START WITH THE INTAKE(S)
Now you can remove the 2 bolts that hold down the intake rockers. You’ll note that the right side bolt is shorter than the left. Take the left side and stick in to the side and it’ll thread into the rocker shaft. Give it a little pull and you can then remove the rocker arm. This picture is the shaft from the exhaust side. You may also see the paper towel I stuffed around the timing chain just in case. IFKYK.
Take the rocker and shaft to the bench and check them. Mine had clear wear on the rollers but the bearings were still good. The shafts also had some wear. This is all academic as we’re putting in all new parts anyways.
I checked the surface of the cams and they all looked smooth. You would rather have the rockers wear than the cams. Dragging a fingernail across the surface should give you a good idea if they are scored or not.
Next, put in the new rockers with the new shafts. Put a little assembly lube on all surfaces (that’s the pink stuff you see in my pics). You’ll also not that the shafts have a slight flat spot (blue arrow) that should be pointing up. That ensures that the oil galley hole (orange arrow) gets oil and we don’t have to do this all over again.
With the new shaft and rocker in you can put in the shorter right side bolt, then unscrew the longer one we used for the shaft and put that in the left side. Tighten to torque specs (12 Nm) and grab your feeler gauge.
Check both intake valves – we’re looking for a number between .07 and .13 mm and write that down in the appropriate area of your X,Y grid. If they are within spec – YAY! You can move on to the other rocker arm.
If they are NOT within Spec we have to do some maths. You’ll need to pull the shaft and rocker out again. Once you do, with a small magnet you can grab the metal shim off of the top of the valve stem. If you are lucky it’ll be laser engraved with a number on one side. If you are not (I wasn’t) you’ll need to measure the thickness of that shim with something. I’ve seen people use digital calipers but all I had was an old fashioned micrometer. We tested it with feeler gauges and it was accurate!
I’m not going to show you how to use a mic but it’s pretty simple. Measure the thickness of the shim you had in there and then do the math to figure out what shim you need to replace it with. You could do that on your piece of paper or… check this out.
The guy who created TrickTracks so that you could Garmin so much better on routes also has a digital spreadsheet. Input what you have, and it’ll tell you what you need!
Here’s the URL: https://tricktracks.org/ and at the bottom of the page you’ll find the link to the calculator. Thanks Scott!
So, now that you know what size shim you need, go over to your shim box and get the one that matches the closest. Confirm that they are the right size, sometimes shims like to go visit their cousins in the next box over.
Go back through the process of reinstalling the rocker arms, tighten it all up and feeler gauge it again.
Within Spec? Most likely, right? If not, do it all over again.
If it is in spec let’s just make sure. Rotate the engine one full cycle (counterclockwise). Get back to TDC on the compression stroke. Now measure again. Still in spec? You would think so, but true story, mine were not – more than once.
Once you are satisfied you have the intakes done and done right let’s move on up to the exhausts. The process is identical to what we just did on the intakes. Make sure you put assembly lube on everything. Clean the sealing surfaces up, install a new gasket and bolt it all back together.
SIDE NOTE: in cleaning my surfaces, Kyle noticed a bug deep in the locating collar on the right side of the head. That spot is completely sealed off when you put the valve cover and gasket on, and this little guy was tits up and dead for a while. How’d he get in there?
We verified that the hole was indeed sealed…
And so we did the sporting thing and left him in there.
With everything back on and bolted up tight we started the motor and it sounded just great! Maybe even a touch quieter than it was previously.
As for what I now have – here’s a look at the final scratch pad. Kyle’s bike is at the top. He required ZERO new shims! NONE at all!
Mine is the set of scribbles below and you can see we kept having to fine adjust shims just to get the right gaps.
I’ll better explain what this all means.
- Exhaust Left: Now has a 2.50 shim and measures out to .09 mm gap.
- Exhaust Right: Now has a 2.40 shim and measures out to .13 mm gap.
- Intake Left: Now has a 2.50 shim and measures out to .10 mm gap.
- Intake Right: Now has a 2.45 shim and measures out to .10 mm gap.
We would put in a shim, measure it, be happy, rotate the motor, measure again, be not so happy and have to adjust to a different shim and measure again. You can see that Exhaust Left had the most iterations of this process while Intake Right had the least.
My old shims might have had the size on them a while ago but that was long ago. By recording my current shim size now, if the lasered size is worn off I still know what it was.
We took our time but really, this is a one to two hour job at most and other than a mic and feeler gauge it doesn’t require much in special tools.
He's an avid hockey fan, rides a mountain bike, sometimes rides a road bike, has a few motorcycles (he had a really fast one, had a big cool orange one, rode a really slow one, and is currently building a perfect "BDR Weapon"). If that isn't enough, he makes cheese and sourdough bread, loves strong beer and good red wine, and poorly plays the Mandolin.
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