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New Owner Has Cam Bearing Wear

15K views 121 replies 11 participants last post by  pdwestman 
#1 ·
So I recently purchased my 2006 KLR with 34,000 miles on it. I have a thread in the introductions section of this forum if you'd like more information. The previous owner didn't know the last time the valve clearances were checked, so recently I decided I should do that and fix the leaky valve cover at the same time

I should state up front while I am no engine expert, I am a fairly experienced mechanic but I am new to motorcycles and KLRs. I have done some light engine work before, and have helped assemble long block car engines as well. However I am no engine builder.

The intake valves were barely in spec so I anticipated ordering shims, the exhaust valves were not in need of adjustment. I removed the camshafts, and I was immediately disappointed at what I saw. Mind you, my phone doesn't take excellent pictures s(I tried to do the best I could).

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As soon as I removed the VC, I saw that this piece of metal had been rattling around the top of the cylinder head. It was located on the intake side of the head. Is this a cam end cap? You can see me placing it at the end of the intake cam to visualize if that's where it's supposed to be. Are these cams supposed to fill with oil once under oil pressure? That was my first concern.

However that wasn't the worst thing. The head journals and some of the cam bearing caps looked (to me) awful in places. I've seen cams/valvetrains with many more miles that looked perfect, and clearly there is significant damage to the aluminum bearing surfaces (in varying degrees). Prior to discovering this, the engine seemed to be running well. No burning oil or awful sounds. Now that I know what it is, I think I might have heard the loose piece of metal rattling around the top of the head before I disassembled.
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The original owner (not who I purchased the bike from) installed a 685 kit from Schnitz, and it's safe to assume something went very wrong to motivate buying the big bore kit. When I just finished replacing the clutch recently I found aluminum chunks (big pieces) in the oil screen that I can only assume were once a piston. I decided to read up on KLR engines a bit before starting this thread, so I am very aware if the engines are run low on oil the top end is the first thing to go. I'm thinking the original owner did this, somehow it blew up the piston, and damaged the journal surfaces enough to be bad but less than catastrophic.
 
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#35 ·
Few have experience with them because they are way outside the definition of "low-hanging fruit" and "inexpensive".

KLRChris may have fiddled with them, perhaps you could look around his site.
 
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#36 ·
The biggest problem with aftermarket cams is that the engine also needs cylinder head porting and adjustable cam sprockets to allow the cams to be degreed/timed to operate/flow as designed. Otherwise, the engine may run Worse!

One very knowledgeable mechanic / machinist / engine tuner extraordinaire built a few very excellent degreeable sprockets a few years ago, Cheaply!
Regrettably he didn't find enough owners with enough patience to properly install them to continue selling them.
I simply didn't have any disposable income at the time. :(

Read this, Adjustable cam gear set for the KLR650 will allow you to move power band And everything else on his site!
Use the drop-down menus and click on Any Bolded or Hi-Lighted word or phrase with-in each section!
Lots to be Learned!!

ps, Tom Schmitz installed a set of KLRChris degreeable cam sprockets. Go to his Souperdoo site!
 
#38 ·
Mini update: the crankshaft plug recommended looks like it should work. The end with the edge measures 17.25mm and the small size tapers a bit below 17mm. After doing some reading I will use red loctite, and use wood, a properly sized socket, and a machine press to press in the KACR into the EX cam fully, and the plug into the IN cam.

In the meantime, I enlarged the "L" hole on top of my airbox some more, and I am currently grinding the header pipe welds smooth for better flow. These things, in addition to a clean air filter, and new spark plug will hopefully bring some life back into the motor with valves freshly re-shimmed.

Today I completed installing the external oil feed with new banjo bolts with the enlarged hole sizes. In the future I will look into the oil filter cavity restrictor mod more. I have found the related threads for this subject, but still have some questions about some of the terminology. I have never heard of drill bits with a numerical system (ex #44 etc) and need to reread everything.

Hoping this is the beginning of the end of the 'fix-it-before-i-ride-it' phase.
 
#39 ·
The plug seemed to work perfectly as far as I can tell, I used red loctite to be safe. The KACR did press in fully which is awesome, and it didn't go in easily... Which is good because I'm pretty confident it won't ever come back out. I can only hope it's oriented correctly as I had no way to remove or index it without risking cam damage. My bike has never had a starting issue so hopefully everything is good.

This has me wondering if my bike is a perfect example of the 'bad Thailand assembly' that I've seen mentioned. Was 2006 first year for Thailand assembly? How else could both the Intake cam plug fall out and the KACR be incompletely inserted/pressed in? I'm baffled by this.

Since my bike was technically in-spec for valve clearances (intake barely), the plug must have come loose since whenever they were last checked. So odd, what would make it pop out after at least 20k or more miles?

I should be able to get a lot of reassembly done tomorrow, no promises as I move slowly and carefully with engines. I have some repainting to do, but can't wait to show off my pig when I'm done. Guess this is end of thread, thanks everyone that gave input.
 
#42 ·
This has me wondering if my bike is a perfect example of the 'bad Thailand assembly' that I've seen mentioned. Was 2006 first year for Thailand assembly? How else could both the Intake cam plug fall out and the KACR be incompletely inserted/pressed in? I'm baffled by this.
Assembly was shifted to Thailand for the 2002 model year. I'm not sure what caused your particular issue but I think it's safe to say that given the hindsight of the last 19 years that there were no big quality control issues inherent with the Thailand assembled bikes. In the old days, I was pretty happy with my 2001 as the last of the Japanese assembled bikes, but now I don't think it much matters and I'd be happy with any 1996 - 2007 model.

2 cents,
Dave
 
#40 · (Edited)
This thread will not end unless you stop posting updates, which I do look forward to.
Such as,
Current CCC at WOT?
Ease of start up? At various temps, at various altitudes?
CCC at WOT after 10k miles?
Valve tappet clearance after 10,000 miles?
CCC at WOT after any valve tappet adjustments?
Oil consumption at 75 mph+ for 200 miles? Times 5 fill-ups?
Oil consumption at 75 mph+ for 200 miles / 1000 miles after installing a #44 / 2.18mm / 0.086" drilled oil control orifice into the oil filter cap 6:00 oil port?
BSL oil report after 1st 3000 miles + a second BSL oil report after 3-5k more miles? Which oil are you using?

It is all up to you.

Ride Safe.
 
#41 · (Edited)
What does CCC stand for? Does BSL mean baseline? Eventually I think I will start a new thread about my personal oil consumption. I added a mini reservoir into the clean-side air box drain hose so that I have a visual representation of how much oil is lost due from crankcase evaporation.

I'll go into all this much more once I get the bike back together and running. Can't say I'll have the chance to go 75mph for 2 hours anytime soon though.
Edit: just realized CCC is cold crank compression
 
#43 ·
Edit: just realized CCC is cold crank compression
Yeap. Cold Cranking Compression at Wide Open Throttle.

Valve tappet clearances & doo hickey adjustments should be checked and / or adjusted after rotating the crankshaft CCW to TDC. (Counter-Clockwise to Top Dead Center)

BSL = BlackStone Laboratories oil analysis company. To see how your engine & its oil are both doing.
 
#45 ·
Throttle position affects compression at startup?
Exactly. ALL Engines are tested for maximum compression at FULL Throttle.
Best to have a fully charged, GOOD battery to avoid a false low reading from too slow of cranking also.

And I don't care which book one might read, it is best to test engine compression at room temperature or even Lower.

If you can't get it Started you can't test fully warmed compression, can you!
 
#46 ·
Alright so today I buttoned the engine back together, and quickly learned why the VC was leaking so bad when I bought the bike... One of the head bosses was stripped... So I ordered a helicoil kit and fixed that, which went smoothly once I removed the electronics bracket and all associated connectors that were in my way.

Bike started right up! Without a doubt, the engine sounds waaaay better than before. Maybe that has something to do with my KACR not contacting the cylinder head OR a loose metal plug rattling around! Valve adjustment couldn't hurt either.

In days ahead I'll be changing the oil, and buying some new fuel hose. I have a thin wall plug socket backordered so that'll have to wait. I need warmer weather to paint the pig though, the gas tank is a mess of the original color and some weird coating a PO put on it (not plastidip).

I'm also pretty proud of a very KLR appropriate mod I did. Idk about everyone else, but somehow I always get junk in the spark plug well. After spending a lot of time cleaning that out I decided I should cover it. Dollar store to the rescue!! I bought a silicone pot holder (safe to 400+ degrees), and trimmed it to fit on top of the head. I just snipped two holes for the temperature sensor and the plug wire. It won't catch everything but it definitely will help!
 
#47 ·
I find the original oem tool kit spark plug socket to be one of the best fitting on the KLR's. At least after stepping over to the bench grinder and putting a 45 degree bevel around the outside of the lower tips of the hex socket. So the corners can't dig into sides of the plug pocket.

I tried to bevel all of the oem spark plug sosckets in the KLR's that we sold from 1987-2016.
 
#48 ·
Well my fixes seem to be holding up. I drove 150 miles today on paved mountain roads. Some cruising, some spirited driving, some slower windy roads. Definitely not extended time at 5500rpm or even 5000rpm, but often going through the usable powerband briefly between turns (3k-5.5k rpm).

It was extremely liberating after all the work I've put into the bike. While riding my temperature gauge only goes up about 1/3rd and I never heard the fan kick on once. The fan is working, if I let the bike idle long enough it warms up to halfway until I'm moving again. I ordered a replacement 195F t-stat for my T-Bob version 1, hopefully that's the fix.

I haven't removed the factory t-stat housing since owning the bike, but my understanding is that they open early (cold) anyway. I might test my old t-stat once I drain the coolant. I'm hoping if it indeed runs warmer after a new t-stat that the oil viscosity difference, however small it might be, helps the engine smooth out a bit. The engine isn't very happy between 2-3k rpm, but seems great everywhere else.

Perhaps a carb cleaning will help with this too. At lower rpms I get intermittent exhaust pops during deceleration, I'm thinking something's either a tad dirty or in need of slight adjustment for more fuel in partial throttle (low throttle) positions. Not going to lie, I plan on riding more before getting into the next project with the bike...as long as nothing breaks haha
 
#49 ·
Hi, I just wanted to comment on your engine. Having had much engine trouble, I am now almost a pro at this. First of all the cams do fill with oil pressure and lubricate the journals so with that cap having a hole or being completely out (either way) it is going to starve the cam journals some oil. That being said, those journals and caps looked salvageable. The way I fixed mine was to sand them smooth using 1200 then 2400 sand paper. I also used a little bit of compound to help lubricate while sanding. I didn't take much material off. Thats important as you don't want a gap when your done. Your just trying to take the surface layer off, Less than a thousandth of an inch. I basically used each sand paper for just a few rubs each, and by the end, it looked brand new shiny smooth. The cams need to be repaired or replaced to have the new plug in the end. If you found chunks, you might consider a couple of oil changes and make sure that you change it when the oil is warm, and while it is still draining pour some new oil in it and drain fill until no more little chunks at the end and no more black oil. Rock it side to side when draining to dislodge chunks and get them to run out the hole. That's why you pour some new oil to help flush it out. I would also invest in a magnetic plug. You said you cleaned the screen, that's good, make sure you also change the filter and check for the pipe and valve inside the filter to make sure everything is proper. Assemble with assembly lube and turn it over without starting it by unhooking the coil wire until you get oil pressure coming out of your cam. Then you can start it. The KaCR seems to be the child of the kick starting era, although removing it is hard to do. You would have to install a plug on the end of the cam which i have not seen for sale. You could buy a hotcam. Those do not come with a KaCR and already have the plug installed. All in all I think your motor is going to OK.
 
#50 ·
In short I already plastigaged the cams, pressed in new plug for In cam, pressed in the KACR fully, checked/adjusted valves, had clutch cover off and inspected that side of engine, rebuilt water pump. Did hot oil and filter change today after about 30 miles. I try to practice due diligence.
 
#54 ·
Since ya'll don't seem bothered by small updates here's one more:

So far the bike doesn't burn a drop of oil. I have done some freeway stints, not an hour long (yet), and a lot of riding in the local mountains.

I really like the bike, and apparently my new clutch springs broke in finally as the lever got a bit easier to actuate the last few rides. I think I've put close to 1k miles on the bike since fixing it, we've had dry weather for March this year so that's been great.

I haven't had the chance yet to install a new thermostat-- because I'd rather ride it haha.

However I have to admit the bike feels somewhat squirrelly at 65+mph speeds. I've noticed my fairly large Parabellum Rally windscreen makes the stock fairing shake around quite a bit at speed, and that has me wondering if that is what's making the bike act funny. Any speeds lower than that feels awesome and stable. I'm going to double check rear wheel alignment as well to be sure. It feels like the bike doesn't want to go straight without lots of small corrections once I'm at freeway speed.

Since my last post I've also installed 2" rox anti vibe risers and JNS lowering foot pegs. I love the ergo change, but I'm still getting used to the shifter feel with the new setup. I have to admit the anti-vibe feature isn't as effective as I thought it would feel. I know this is a subjective measure, but it feels like maybe ~10-15 percent reduction. Maybe the big bore piston on my bike already reduced the vibes sufficiently to where there isn't much left (for a big single).

Last is the part no one wants to hear from yet another person. I wish the bike had a bit more power- There I confess!! Before looking into KLRs and buying one I already knew they're considered slower bikes, but I like everything else about them too much for me to consider another bike. Since it's a 685 already, has a good exhaust, ported gen II header, Lmod/ snorkel gone, next I'm going to try using tape on the lower third of the airbox door area (Klr Chris style). At some point I will tweak the carb (1 step at a time of course) but don't want to get into that can of worms just yet.
 
#56 ·
It feels like the bike doesn't want to go straight without lots of small corrections once I'm at freeway speed.
I'm Always happy to read an update. Especially a positive one. :)
How flat/square is the center 1/3rd of your rear tire worn?

And I'll recommend a minimum of 32 psi front & 30 psi rear for tire pressures! Always 2 psi higher in the skinny front tire!!
 
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#57 ·
Try adding some preload to the rear if you haven't done that already. A saggy rear contributes to front end wiggle on the road at speed, in addition to the afore mentioned tire pressure. That big windscreen with also increase drag. Maybe get a more streamlined front fender too.
Be sure your jetting is set up properly.
 
#58 ·
Before my ride today I had both tires set at 30 psi, sounds like that was a bit low. I'll up to Rear 32 Front 34psi. The rear tire will definitely need replacing by next winter, maybe sooner. Could normal wear cause instability? Seems like it would do the opposite.

I wouldn't think the windscreen adds too much drag as my head and shoulders are above/wider-than the screen. I'm 6'5 with wide shoulders, and I was smart enough to dip my head below screen level at speed to see if it affected the instability-nope. I might even take the screen off and go for a ride to see if that's what's causing it.
 
#59 · (Edited)
I'll disagree with Paul on the air pressure. On the street, 34-36 rear for rear tires, and 32-34 or so front. Much less weight on the front.
Tire wear can cause weird handling. The closer to square it gets, the crummier it feels. Let it go too long and it's like magic when it's with a new tire. The rims on the KLR are actually too narrow for the weight and recommended tire sizes. Putting wider tires on the stock rims makes it even worse. The rim size thing isn't just my opinion, it's on the tire and wheel mfr sites. :)
If you have the small stock screen, give it a try for a bit. A quiet helmet and a snug collar will quiet things down nicely. If you have a helmet with a visor, no bueno. Either way, whatever works. :)
Good luck!
 
#61 ·
Paul is correct about scalloped tires causing or contributing to handlebar wag/front end shake. On a number of bikes I’ve owned, replacing the front tire will stop those handlebar shakes. And then in a few thousand miles they come back as the tire wears.
 
#62 ·
My front tire has lots of miles left in it. Can someone describe the term scalloping differently?

It's easier for me to visualize tread position in a way like "on top of the tire the "V" is pointing forward" etc. I understand most of what was last shared, but terminology is not perfectly clear to me. My current understanding is that the V should point forward at the top of the tire to push water etc to the outside. At least that's how most (all?) car tires are designed to work
 
#63 ·
It would be easier to describe with a picture. What you see in the scalloped tire is what I will call alternating high and low spots as you go around the circumference of the tire. It's usually not just in the middle, but slightly off center, and both sides. Some tires do it more than others.
I understand what you are saying regarding water, I've also seen people argue the vee going the other way for increased traction in braking, or so the theory goes.
IMO if one runs too high pressure in the front you lose traction. The contact patch will be smaller in cornering with higher pressures. Yes, there is weight transfer in braking, and the weight transfer gives a wider contact patch. Too high a pressure and the tire will not conform, reducing the contact patch and traction. I've never seen a bent rim from proper pressure in the KLR, always off road with low pressure hitting a rock.
YMMV
 
#64 · (Edited)
On a front motorcycle tire you need an upside(-down) vee when looking at the top front of the tire coming out from under the fender. So the point touches down LAST. ./\.

Scalloping is when the tread blocks or knobs are worn at a taper. Most scalloping occurs just off-center to both the LH & RH sides. In the RH lane drive countries there will always be a little more wear on the LH side of motorcycle tires, because of slope of highway and we tend to make more LH turns.

In the UK, Australia and such they will wear the RH sides of their tires more.
 
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#67 ·
I definitely don't want to reduce front end traction.
Front end traction is much more a matter of the rubber compound of the tire chosen, than it is of the air pressure in the tire, at anywheres near Legal speeds on any paved highway, imo.
2 to 4 psi too low of front tire pressure is worse than 2 to 4 psi too high of front tire pressure at legal speeds.
 
#66 ·
I usually run 36/34 on the highway. I have never had any wobble issues. Please note that I do this with Kenda K761, so it is with a more road-oriented tire.
 
#68 ·
I too run higher pressures on the front; it takes a bigger hit on obstacles and is more prone to rim damage. Kawi recommends the same front and rear unless you are carrying a passenger or heavily loaded. I always ran 2 psi more in the front of our offroad race bikes, as did all the other racers that I'm aware of and lastly, the larger rear tire can support more weight at the same PSI as the smaller front.

2 cents,
Dave
 
#69 ·
My wobble post:

Way too many people think that addressing the symptoms by dealing with handguards, fenders, fork braces, etc. are the answer rather than dealing with the real issue which is related to suspension setup and loading. I'm not convinced that the KLR is any more susceptible to instability than any other bike with long travel, lightly damped suspension and the Owner's have a propensity for severe and uneven loading.



There are some problems that need to be checked;

- bad/lose head bearings

- condition of wheel bearings and suspension bushings

- wheel and tire condition and appropriate tire pressures.



.....beyond that, It's settings;

- proper sag settings and adequate damping

- proper bike loading

- avoiding inappropriately un-aerodynamic loads



addressing the symptoms rather than the cause can help but IMO shouldn't be done until all the aforementioned items are checked and corrected if necessary. Nonetheless these can help stability;



- fork brace

- smaller fender or lowered fender (I use a polisport as I hate both the supermoto and low mounted fenders)

- consider tank bags instead of putting everything in huge panniers which affects both weight loading and aerodynamics.





My 2001 had some high speed issues that went away as soon as the sag was set properly....and after my Cogent suspension was installed, both my KLR's have been rock steady.....even with full knobbies and low tire pressures (20 - 22PSI). Lastly, as others have mentioned, the rider also plays a part; keep a relaxed light grip on the bars and don't tighten up. Changing your position (move forward/lean forward) can help too.



2 cents,

Dave
 
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