CCT Spring Length

871 Views 6 Replies 2 Participants Last post by spray____, Sep 6, 2016

spray____

Discussion Starter · Aug 11, 2016

2006 ZX-10R with about 31,000km

I've been playing around with my CCT the last few weeks. I figure I should write all the info about everything I've done and experienced in case someone can provide guidance.

Back a few months ago when I did my valves and fixed my valve spring retainers, I put in a manual CCT in, but I've never been totally comfortable that I got the tension set correctly. I should have checked the length on the auto CCT, but didn't think it was necessary at the time. At first I did it finger tight while rotating the engine, then backed it out 1/4 turn. The chain seemed to make a lot of noise and I could feel some slack when I revved the engine and/or let out the clutch in neutral, so I tightened it up a bit more until the slack was gone and it got quieter. After that, I could hear a loud ticking noise coming from the left side of the engine. Seemed to be almost gone around 60°C, and get louder up to 90°C.

I thought maybe I did something wrong with the valves, so I ripped the entire thing apart again and checked. Everything was fine. Keepers are all seated and spaced nicely, and valve clearance is on the loose side, but still in spec everywhere. And the bike had been sitting for a few days, so was definitely at the right temp when I checked.

I got paranoid I had it too tight, and it was causing the noise, so I decided to go back to the auto CCT and see what happened. When I was doing it I noticed something strange. Playing with it out of the bike, the spring inside doesn't look like it applies enough pressure to extend the tensioner all the way. When I put the spring in with the little metal rod and tighten the big bolt on the back, it pushes the plunger out maybe 2/3 of the total distance it will travel. The plunger doesn't seem stuck (I oiled all around it and it slides as smooth as it can with the little locker pressing against it). The spring doesn't look visibly damaged or distorted. This seemed a bit strange to me. I tried looking up a diagram, but it only shows the tensioner as one full assembly. Doesn't seem shared with any other bikes, although that could be the entire assembly.

Haven't been able to put more than about 50km since the auto CCT went back in. I did the 5th gear roll back to adjust the tension, and have had it up to full temperature for a while. There is a lot more noise on the right/chain side of the engine than there used to be and the bike in general feels more "rattely" than before, but I don't feel the slack in the throttle like I did with the manual one. Not sure if the ticking has died down, or is just more hidden in the other noise.

Bike runs great, full power and on all cylinders.
Not loosing any coolant.
Not loosing any oil, at least not enough to notice. Haven't topped it up in the last 3000km and it's well within the sigh glass.

Anyone have thoughts or knowledge about the auto tensioner?
Any idea what the standing length of that spring should be?
Is a ticking noise from the LEFT side of the engine at all normal?

I'll try and get a video later to show the noise I'm talking about, maybe someone can let me know if it's normal or not.

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SkyDork

· #2 · Aug 11, 2016

There are no free length spring specs on it. It wouldn't matter anyway. The tensioner is considered tight when the noise stops. Each bike will be different and each will achieve their own tightness differently. It would be very hard to overtighten the tensioner unless you try to manually set it outside the bike and force it back into the motor with the mounting bolts.

Take the spring and rod out of the auto tensioner. Install the body back in the bike once you've reset it to the minimum point. Once it's in the bike, use a small screw driver or ratchet extension or any type of rigid push rod. Insert that tool into the tensioner and use your hand to manually extend the CCT plunger (like the spring is supposed to do). Turn the crank a couple of rotations while still putting pressure on your pushrod to see if it will click out any more as the cams turn and the chain tension changes. Then, reinstall the spring and guide rod and you're done.

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spray____

Discussion Starter · #3 · Aug 12, 2016

Sure, I know they would all be different, but I was just worried it's not applying enough pressure to take up the slack. The auto CCT with that spring the way it is doesn't seem to have much force or range to it.

Went out for a good ride last night, and seems as good as it's ever been. Can't feel chain slack in the throttle, and it sounds and feels smooth from a cold start. As it warms up it does get a little more buzzy, and the left side ticking becomes audible up until about 4-5k rpm.

Might give that manual adjustment a go in the future, but I'm fairly confident now the auto tensioner is doing it's job. The tick on the left side is what's driving me crazy. Tried to track it down with a stethoscope, but I really need to do it with the airbox and heatshield off to be able to access anything. The loudest I've been able to pinpoint it to so far is the left side of the throttle body.

Sorry for the text dump. I've been meaning to post something for a while and once I start typing it all comes out

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SkyDork

· #4 · Aug 12, 2016

spray____ said:
Sure, I know they would all be different, but I was just worried it's not applying enough pressure to take up the slack. The auto CCT with that spring the way it is doesn't seem to have much force or range to it.

Went out for a good ride last night, and seems as good as it's ever been. Can't feel chain slack in the throttle, and it sounds and feels smooth from a cold start. As it warms up it does get a little more buzzy, and the left side ticking becomes audible up until about 4-5k rpm.

Might give that manual adjustment a go in the future, but I'm fairly confident now the auto tensioner is doing it's job. The tick on the left side is what's driving me crazy. Tried to track it down with a stethoscope, but I really need to do it with the airbox and heatshield off to be able to access anything. The loudest I've been able to pinpoint it to so far is the left side of the throttle body.

Sorry for the text dump. I've been meaning to post something for a while and once I start typing it all comes out

The spring will not apply as much force as the plunger extends and the spring potential energy is less. If you've got it in there and there's no rattle, then it should be good.

There's not much on the left side of the motor that could be ticking. The alternator is low in the motor, and that's about it. The cams up top could be if the valve clearances are off, but they usually tighten up over time, not loosen (usually). Guess you're just going to have to keep hunting around for the source at this point.

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spray____

Discussion Starter · #5 · Aug 12, 2016

I think so. Went for another ride today and got stuck in traffic with my low fuel light on. With the engine around 95°C and an empty tank the ticking sounds is incredibly loud. Loud to the point where I feel people around me are noticing. I think I'm going to pull things apart and get the stethoscope out.

What about a fuel injector? I've heard they can tick loudly.

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SkyDork

· #6 · Aug 12, 2016

The fuel injectors will tick, but they shouldn't be that loud. If the sounds gets louder with low fuel and an empty tank, I'd be more inclined to think it's your fuel pump that's causing it.

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spray____

Discussion Starter · #7 · Sep 6, 2016

A little late, but I thought I'd update the thread.

Everything seems fine. I'm confident this is all in my head.

I pulled the airbox off and listened with the stethoscope and can't find anything abnormal. The sounds is still pretty loud, especially above 90°C when near an empty tank, but it doesn't seem to be coming from anywhere specific. Injectors all tick, but equally and nothing abnormal. There is ticking coming from the intake side of the head, but it's also equally distributed across all cylinders. I already ripped the valve cover off to recheck clearances and the rest of my work and it's fine.

I'm going to attribute this to me being sensitive, to Kawi's being excessively noisy, and to having the clearance on the loose end of spec.

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