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Discussion Starter · #1 ·
I'm an avid motorcyclist and currently have 7 bikes on hand. I've been doing all my own maintenance since 1973 and feel confident with routine matters like shimming a valve train. The '07 650R has me defeated right now. Disassembly was uneventful and measurements indicated several shims were at the low end of clearance. Between swapping shims and spares on hand there was no need to order replacements. Reassembly of cams and tensioner was routine. I began to rotate the engine clockwise and got about 10 cam sprocket teeth before I hit a hard lock. Hmmm, maybe the chain tensioner. Removed chain tensioner and rotated again. If I recall, a cam sprocket(s) jumped a tooth because of slack with no tensioner so the intake cam was loosened, chain adjusted on the sprocket and the intake cam retorqued. Same problem - hard lock rotating forward 10 teeth or so. Next, removed both cams and all buckets. Inspected shims for proper seating in their cavities. Buckets and cams reinstalled. Checked alignment at 2T through view port and doublechecked that cam marks aligned with the deck top and 180 degrees apart. Check. Same problem rotating forward. Rotate engine backwards and eventually hit hard lock roughly 350 degrees backwards. New theory - something has fallen though spark plug hole or something is impeding the lower cam chain gear. Need borescope or maybe take right side cover off. Problem with theory - I did not drop anything into the engine. Also, cylinder #2 is falling as I rotate forward and cylinder 1 is still low so pistons probably not hitting anything. Has to be something impeding the lower gear. Need to figure out how to view that area. Nagging thought that Kawasaki's weird neutral finder might be involved. Anyone have ideas?

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Discussion Starter · #3 ·
Have you done a thorough search for a loose shim in the head? Around the valve spring areas and under where a cam lobe might be stopped by a stray shim?
After the problem appeared I proceeded to pull the cams, buckets and shims (twice) and reassemble. I can do it blindfolded now. Today I pulled the clutch cover to make sure nothing is jamming the lower gear. Nothing found. I'm looking for a bore scope product to better view the combustion chambers and camchain area.
 

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Discussion Starter · #5 ·
How about the cam blocks? Are they different and could possibly be swapped between intake and exhaust cams?
I've done quite a bit more investigating on this. With the clutch cover off and camchain tensioner remove it's easy to eliminate an obstruction to the camchain or problem with the tensioner. That leaves the combustion chamber as a likely cause. All buckets fully rise when the cam lobe is not applying pressure push in as the lobe applies pressure. No binding there. I've rotated both pistons into various positions and used a wire probe to detect anything that may have fallen in. Nothing found. I measured where the lock occurs in relation to piston position. The lock occurs when #2 is dropping past TDC and also when #1 is approaching TDC. I'm thinking the problem is somehow a valve that's not retracting. I do recall that after shimming and when first rotating the engine there was a slight catch then pop upwards of the bucket on #2 exhaust valve on the right. If there is a problem there what would the remedy be?
 

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Discussion Starter · #6 ·
I've done quite a bit more investigating on this. With the clutch cover off and camchain tensioner remove it's easy to eliminate an obstruction to the camchain or problem with the tensioner. That leaves the combustion chamber as a likely cause. All buckets fully rise when the cam lobe is not applying pressure push in as the lobe applies pressure. No binding there. I've rotated both pistons into various positions and used a wire probe to detect anything that may have fallen in. Nothing found. I measured where the lock occurs in relation to piston position. The lock occurs when #2 is dropping past TDC and also when #1 is approaching TDC. I'm thinking the problem is somehow a valve that's not retracting. I do recall that after shimming and when first rotating the engine there was a slight catch then pop upwards of the bucket on #2 exhaust valve on the right. If there is a problem there what would the remedy be?
PS Good thought on cam blocks but they are marked IN and EX with the top of the lettering towards the front of the bike.
 

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You definitely working through this and addressed a thought I had about the cam chain and guides. Look at the top of the right, #2 exhaust valve. Verify you have two valve spring keepers still in position and an equal small gap between the two keepers. Also, have you noticed the suspect exhaust valve spring retainer having a slightly different position as it sits in the head? Maybe not if a typical shim size still produces the correct clearance. Any other debris in the valve spring areas?

The other though is that as easy as the cams can be removed, you aren't that far from being able to remove the cylinder head. That would definitely reveal or clear the problem. Just need some coolant and a head gasket.

Before you started the valve clearance check and adjustment, did the engine sound ok? Or, is the check due by mileage?
 

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Discussion Starter · #8 ·
You definitely working through this and addressed a thought I had about the cam chain and guides. Look at the top of the right, #2 exhaust valve. Verify you have two valve spring keepers still in position and an equal small gap between the two keepers. Also, have you noticed the suspect exhaust valve spring retainer having a slightly different position as it sits in the head? Maybe not if a typical shim size still produces the correct clearance. Any other debris in the valve spring areas?

The other though is that as easy as the cams can be removed, you aren't that far from being able to remove the cylinder head. That would definitely reveal or clear the problem. Just need some coolant and a head gasket.

Before you started the valve clearance check and adjustment, did the engine sound ok? Or, is the check due by mileage?
Thanks much for the reply. Someone cares! I'm going to pull the buckets again tonight and look for the keepers as you suggest. Not sure what can be seen from the top but will investigate.

The engine ran perfectly from startup with cold and hot idle spot on and revved to redline with absolutely perfect and linear throttle response. That makes it all the more depressing. Redline is 11 and because of the power curves the motor should never be run past 9 or so and so I was looking forward to a reliable, long lived engine. I've gone all these years without having to pull a head. I over maintain and am careful about warmup, etc. and consequently don't wear out engines. I'll have to look into whether this 650 motor needs to be removed from the frame to pull the head. I suspect it does.

My latest thought is that cams were pulled when the piston was at BDC instead of TDC so I'm going to check that tonight upon reassembly. Maybe cams just out of phase? Also, a scope with several nice attachments is incoming and might reveal the issue.
 

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Yeah, I'm curious about the cause of this stoppage.

Cam timing is a real thing. Definitly get that right. Check and recheck before releasing the chain tensioner too. You can use a short tool to manual press the chain guide to be extra sure the timing is correct. Also, when checking the cam timing, don't rotate the engine backwards to check timing marks. If you have to back-up, do so enough that the crank can be rotated forward to properly take up the chain slack. Sounds like you are aware of this, so just a reminder.

If you can see the pistons through the spark plug holes, try a long piece of wire to identify the lower and higher pistons.
 

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Discussion Starter · #10 ·
Tonight's testing of the hard lock problem had interesting and inconclusive results. Clockwise roation "Test 1" reveals the hard lock occurs while piston 1 is near BDC and rising and piston 2 is just after TDC and is falling. That would seem to indicated there's no piston to valve contact happening. Next, I removed the cams and buckets and did a recount on bolts and dowels. All are accounted for. All springs and top keepers are at an identical height. I can run a plastic ziptie around the perimeter of each spring with no obstruction. "Test 2" is rotating the engine through several full revolutions while pulling the cam chain upwards with my other hand. This second test leads me to believe that piston to valve contact just has to be the culprit BUT that seems to have been ruled out by Test 1. Next step is waiting for and using the bore scope.
 

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Some good information there. Have you been able to inspect the entire cam chain? Like mark one link and pull, or rotate all the way around? The cams would have to be out to do this. Also by doing this, you could confirm the crank is capable of rotating 360 degrees.

Sounds like you have access to a borescope. Pretty cool. I haven't seen on since my Army Aviation days. Our engine mechanics had them for inspections of compressor blades--or, as they needed for troubleshooting.
 

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Discussion Starter · #12 ·
Some good information there. Have you been able to inspect the entire cam chain? Like mark one link and pull, or rotate all the way around? The cams would have to be out to do this. Also by doing this, you could confirm the crank is capable of rotating 360 degrees.

Sounds like you have access to a borescope. Pretty cool. I haven't seen on since my Army Aviation days. Our engine mechanics had them for inspections of compressor blades--or, as they needed for troubleshooting.
The cams are out. I stretch the chain above the deck with my free hand, rotate the engine a few inches and readjust my grip on the chain. In short order I've rotated the engine 360, then 720 or more. The engine is turning freely when you take the cams, chain and tensioner out of the equasion.
 

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Discussion Starter · #13 ·
Conclusion to how this shim job went bad; blame to myself and Kawasaki's service manual: Today I'm looking at the lower camchain gear. That gear has duplicate 1T and 2T markings. 2T markings are found 90 degrees apart from each other. This is fully visible only with the clutch cover off and is not mentioned in the service manual. If you follow the Kawasaki procedure, you set the 2T marker position then install the cams with the appropriate markings on the upper cam gears even with the deck. If you pick the wrong 2T marker, the #2 piston will not be at TDC when you install the cams. After shimming and as you rotate the engine, #2 piston is going to impact an exhaust valve. The lesson is to use a screwdriver or something similar to make sure the piston is at TDC before installing the cams. This snafu is going to require an engine removal, head pull and fix to the affected valves. I'll verify the valve damage when my endoscope arrives.

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Interesting to hear about how there is not inspection cover for timing marks; and yeah, that's a step should be mentioned in the manual. Still it might not be necessary to remove the clutch cover to check valve clearances. Here's a tip. Watch the intake cam lobes. Once it depresses the intake valves and begins to close, that piston is on its way to TDC. At TDC, the intake and exhaust cam lobs face away from each other. It'll be a while before you have to do another valve clearance check, but you could get a piston to TDC, remove the chain tensioner, then remove the cams to replace shims and not remove the clutch cover. (never rotating the crank at that point)

As for a possible bent valve, I'd not suspect that actually happened just yet as the valve most likely made flat contact with the piston--just a stop of the rotation. You could install the cams and do a compression check. Also suspecting that everything could be buttoned-up and start the engine. Once at idle, immediately monitor the exhaust header pipes for heat build-up. The two should be equal.
 

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Discussion Starter · #15 · (Edited)
There are two removable access ports on the clutch cover. One is large enough for a ratchet to turn the engine and the other is a penny sized view port for the timing marks. After obsessively rerunning the repair in my mind it's all come back. To begin the job, I rotated to the 1T mark to make measurements thinking what's the difference. Between my eyesight, the lighting, recently lost flashlights loaned out during a power outage and the small view port plus having forgotten to pull the plugs, I was OK with 1T (instead of 2T). I made the measurements, removed the cams and installed the shims. Upon reassembly and after rereading the procedure, I rotated to the wrong 2T mark (the one 90 degrees out) and installed the cams. In my mind there's nothing possibly incorrect about the reassembly so I compounded the problem by rotating through the interference causing damage that created the hard lock. I probably knocked keepers off a valve that's now hanging too low. That just a guess. I'd be delighted to hear a fix that doesn't require pulling the head.
 

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Got it. It's an experience. Be glad it's not a four cylinder engine. Those timing reference marks are ridiculous really. Why have two of the same? Maybe, that target is used on more than one bike engine.

So you have a valve stem lower than others and suspecting it's a bent valve? Does the engine really have to be removed in order to remove the cylinder head? Maybe the front of the engine could be lowered enough to remove the head?

If you have to replace a valve and don't have a spring compressor, maybe an auto parts store has one to loan. A c-clamp version would be easiest. I used to have one, but when I left the tech industry that was one tool I let go. Haven't had a need for it since either.
 

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Discussion Starter · #17 ·
Got it. It's an experience. Be glad it's not a four cylinder engine. Those timing reference marks are ridiculous really. Why have two of the same? Maybe, that target is used on more than one bike engine.

So you have a valve stem lower than others and suspecting it's a bent valve? Does the engine really have to be removed in order to remove the cylinder head? Maybe the front of the engine could be lowered enough to remove the head?

If you have to replace a valve and don't have a spring compressor, maybe an auto parts store has one to loan. A c-clamp version would be easiest. I used to have one, but when I left the tech industry that was one tool I let go. Haven't had a need for it since either.
After some consideration I started looking around at parts. I found an immaculate head with only 3K miles. The price was $233 delivered so I went ahead with the order even though repairs on the old head might be easy. I can always repair and sell the old one. It does appear the front motor mount can be removed to drop the engine forward enough to replace the head. That's my plan right now. I'm a bit further along than the pictures show and will proceed as parts arrive.
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Definitely a lot going on there, huh? It's been a awhile since I had to remove an engine--the GPz750turbo I got back in '00. The frame was bent at the steering head. The price for that head seems good.

Can't help but notice you have a several irons in the fire around your shop. And with style given the rugs. (y)
 

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Discussion Starter · #19 ·
Definitely a lot going on there, huh? It's been a awhile since I had to remove an engine--the GPz750turbo I got back in '00. The frame was bent at the steering head. The price for that head seems good.

Can't help but notice you have a several irons in the fire around your shop. And with style given the rugs. (y)
I was in the middle of reassembling a '75 Goldwing when the 650R was acquired. Thought I'd switch gears and get the Kawi fully sorted out. Fortunately I have enough room to accommodate both. A few feet away but not pictured are my '96 Triumph Trident and '07 Honda Transalp. You can see a little of the '00 TT600, the '03 SV1000S and the '92 ST1100. All bikes except the Wing and 650R in perfect running condition.
 

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Has the replacement head been delivered? Hopefully it is as expected for you. Also, if upon removal of the head and you see the valves are seated as they should, would you correct what you saw from the top side and reinstall it?
 
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