A strange noise

[Meshuggah]

but i think there is tension at the moment, probably not the perfect one. It is because the the CCT won't go forward or backward unless you turn the screw inside. When i mounted it back, I screw it to get as much tension as I could and now I believe it stays there in place.

 

[Serzedo]

Better to have that expense and sell the motorcycle after.

"V"

 

[Motogiro]

but i think there is tension at the moment, probably not the perfect one. It is because the the CCT won't go forward or backward unless you turn the screw inside. When i mounted it back, I screw it to get as much tension as I could and now I believe it stays there in place.

I would stop using the bike. Get a new replacement OEM or an APE CCT. You may cause other problems with an over tightened chain causing undo wear on the cam chain guides or breakage. You don't want the cams going out of time...

 

[SandyN]

Post 119 might be a worthwhile read...

Think Bike

My Aplogies; that link requires a sign in. Herewith the comment made by the person who repaired "Grommit"'s bike.

What I've just found interesting is that he fixed the spring.


FZ update: The bike is now here with me. It came as one big lump and several boxes. A leak test on the cylinders showed that 2,3 & 4 was within spec. with around 6 to 8 % leakage. No. 1 had 100% leakage, so off with the head.... I found a plastic fairing clip stuck in the R/H inlet valve - removed it and checked for sealing. The valve survived. Then the cause of the breakdown came to light. The exhaust valves left gentle marks in the carbon layer on all the pistons. This happens when the cam timing goes out. Still no damage here, all pistons and valves survived. Why did the cam timing wander off ? The answer is in the tensioner - the driving spring broke.... The chain must have been loose for some time already. I fixed the spring and assembled the whole lot. Engine has good compression now and the valve clearances are all within limits. I must just get the rest of the engine parts from Grommit then we can see if it makes music again.

 

[Meshuggah]

how did he fix the spring?

 

[SandyN]

how did he fix the spring?

I have no idea. I don't know the man personally but I could ask?

Edit: PM sent to "Iron Man"

 

[Meshuggah]

try but I don't think is possible. the all CCT looks like industrially sealed. damn, the company that sells the CCT just told me I have to wait like 15 days cause it's a special item

 

[TownsendsFJR1300]

how did he fix the spring?

In post #7, it clearly shows the unit NOT EXTENDING, in its present state, its junk.


If can post some close up pic's of it, there's likely some tabs that can bent over to open it up/inspect, maybe install a new spring, etc.

It got put together, it can come apart.

I would still install your new one once you get it, BUT riding the way it is, my moneys on the engine will be junk before then..

 

[FinalImpact]

If its NOT AN OPTION TO PARK IT, perhaps an option is to lock it in place... As noted, it may not appear to move willingly, but that doesn't mean it won't while subject to so many vibrations. If it decides to move - could be total loss engine wise. It must be locked.

Option: Remove it, clean the threads with Acetone or MAF Cleaner or something like that. Apply PERMANENT THREAD LOCK.
Quickly install CCT and gently snug up chain slack using the screw. Run the engine.
Too loose you hear the chain rub. To tight, the engine RPM drops. Hit the middle and let it sit for 24 hours to cure.


Thread about opening the CCT... Some pictures.
Cam chain tensioner braked into pieces and assebled again. don't open it up!

 

[TownsendsFJR1300]

Ozarkmans second picture; https://www.flickr.com/photos/123914614@N06/16334486742/ appears as if there's a thin "C" clip possibly holding it together.

Looks / sounds like that main spring broke on the Op's...

 

[FinalImpact]

This? The external snap ring is all there is holding the assembly (main body). Spring on the left attempts to WIND and apply rotation to the worm drive. The Larger coil on the right is to apply pressure.
The cup with the 4 tangs prevents rotation so the spring on the left has something to act against. The failure mode is the tang breaking off the spring so it no longer tries to wind the drive into the chain.

 

[SandyN]

So it is "fixable". The trick would be to get enough tension on the rotation spring I suppose.

 

[TownsendsFJR1300]

This? The external snap ring is all there is holding the assembly (main body). Spring on the left attempts to WIND and apply rotation to the worm drive. The Larger coil on the right is to apply pressure.
The cup with the 4 tangs prevents rotation so the spring on the left has something to act against. The failure mode is the tang breaking off the spring so it no longer tries to wind the drive into the chain.

Ok, so the larger, thinner, outer, spring, on the end, that tang busts off is whats generally failing? Interesting.

There isn't much to that spring. So much (your engine) counts on that bend spring end to NOT fail...

Thanks for the explanation.

 

[TownsendsFJR1300]

So it is "fixable". The trick would be to get enough tension on the rotation spring I suppose.

Even if you did re-assemble it properly, you would have had to "fix" (re-bend) that spring end.

First, for such a critical part, I wouldn't trust re-bending it as a fix. It failed over time, its going to fail again, (probably sooner).

Upon re-assembling, you really wouldn't have a starting point or know how much tension to wind into the unit (a big ???). Especially if it was too loose, potentially disastrous results.


On my original 1989 KLR 250, the cam chain is easily twice as long as the FZ. Years gone back, I started getting chain slap inside. The local, two man shop, heard it and told me to pull it off right there. (the tensioner is much different than the FZ). He put one or two extra winds in the spring (no disassembly) and I re-installed it.. Nice and quiet. The spring, (especially with an older, stretched chain) didn't have enough tension towards full extension. I'd note, I kept the original cam chain in that engine until I sold it with 73,000 miles on the clock.. LS crank bearing would blow (bearing cage actually came apart) every 32,000 miles (and again at 64,000 miles).

 

[FinalImpact]

So it is "fixable". The trick would be to get enough tension on the rotation spring I suppose.

Considering springs are shaped and then 'heat treated' to produce the desired rate and consistency, I would say NO as its going to break if bent. Major gamble if it doesn't break then and there. And as noted, how many winds does it take to apply proper tension??? One could only count a good one and we have few volunteers to do that.


Due consideration of using loctite to stop it, you'd never get it there with without taking it apart. Which, if that spring is broke, well - its easily doable now!

 

[SandyN]

Guys, I have enjoyed this thread and have learnt a lot.

Here is Iron Man's reply to my query: -

Hi Sandy

The tensioner works on a rotary screw action. The spring that turns it in, is wound around the tensioner body. The hook on the one end always breaks off resulting in a noisy camchain. A temporary cure is just to bend a new hook on the end of the spring and re-install it in the normal way.

The tensioner works works automatically. just let the wheel go and the rest will happen by itself.

Yes I did replace Grommits tensioner as the camchain had bad links in it and it kept on damaging the tensioner when he over revved it.

The question on my mind is now, "how does a cam chain develop bad links?" Has anyone else had this happen?

 

[SandyN]

Any updates on this Meshuggah?

 

[Meshuggah]

Hello everyone and apologies for not replying early. SO at the end I parked the bike as you advised, cause I didn't wont to risk.
I ordered and got a new CCT after 2 weeks :-/ and put it back on.
but I'm pretty sure I must have mess the timing up when I tried to install the old one because now the bike makes a popping noise on the other side (left side if you sit on it).
I suppose it may have skipped a tooth?
what I'm trying to do now it is to remove the valve cover and check if when I put the T mark in line on the cracnksafht, the camsahft lobes ( i think they are called this way) are in the right position ( facing off from each other).
before removing the valve cover, do I really need to drain the radiator? Can't I just detach all the tubes and remove the cover or coolant will spill from there?
once again thanks for your help on this matter.

 

[TownsendsFJR1300]

It likely did jump a tooth when you ran it with the broken CCT even just for a moment.

Why your under there and checking marks, check valve clearances. Hopefully you didn't bend a valve that's now stuck partially open..

As for what specifically has to come off, do a search, there's plenty of threads on it.

(IDK as I haven't had my valve cover off or any issues)

 

[Meshuggah]

It likely did jump a tooth when you ran it with the broken CCT even just for a moment.

Why your under there and checking marks, check valve clearances. Hopefully you didn't bend a valve that's now stuck partially open..

As for what specifically has to come off, do a search, there's plenty of threads on it.

(IDK as I haven't had my valve cover off or any issues)

Thanks. the T mark and the I and E mark would not align when the T marks was aligned with the frame mark. no matter what I did. So at the end I had to remove the camshafts and position them to align with the T mark. now I've mounted everything back again but I will have to continue another day for the valve clearance. I may as well do it. Everything has been removed and I'm due for it at 23000 miles.

As you can see in the picture they were not aligned
one last thing. In one of the camshaft I saw the little scraping/marking or whatever it is. any idea?


when I removed the spark plugs, the one coming out from cylinder number 2 was darker then the others. do you guys know why?
thanks
thanks