Valve adjustment no good?

[n4mwd]

Originally Posted by The_big_dill

If it is loose, could it cause more problems?

You can set your torque wrench to 50 ft-lbs and try retorquing it, but I would leave it alone because the engine ran with the starting fluid. Time to put the carbs back on and go riding.

EDIT: After you make sure the cam chain is tight that is.

[The_big_dill]

Originally Posted by n4mwd

You can set your torque wrench to 50 ft-lbs and try retorquing it, but I would leave it alone because the engine ran with the starting fluid. Time to put the carbs back on and go riding.

EDIT: After you make sure the cam chain is tight that is.

Unfortunately, the cam chain was not much tighter than it use to be. I am going to run it and see how it sounds, if its really bad then I will have to figure out why the chain does not have enough tension.
Posted via Mobile Device

[n4mwd]

Originally Posted by The_big_dill

Unfortunately, the cam chain was not much tighter than it use to be. I am going to run it and see how it sounds, if its really bad then I will have to figure out why the chain does not have enough tension.
Posted via Mobile Device

I forget, How many miles on it again?

If the CCT hinge is working properly, then the chain may have stretched. Were you able to get satisfactory tension by poking down into the CCT hole with a socket extension?

Its hard to do, but you can measure the chain to see if it stretched. If it did, the engine usually has to be split in order to replace it.

[The_big_dill]

Originally Posted by n4mwd

I forget, How many miles on it again?

If the CCT hinge is working properly, then the chain may have stretched. Were you able to get satisfactory tension by poking down into the CCT hole with a socket extension?

Its hard to do, but you can measure the chain to see if it stretched. If it did, the engine usually has to be split in order to replace it.

43000km.

That's a good point, I don't think I was able to get the CCT mechanism manually tension the chain properly.
Posted via Mobile Device

[n4mwd]

Originally Posted by The_big_dill

43000km.

That's a good point, I don't think I was able to get the CCT mechanism manually tension the chain properly.
Posted via Mobile Device

I think motofool posted the instructions in post #4. The problem is that you can't measure the required number of links. You just have to extrapolate the best you can.

[The_big_dill]

Well i spent the day after school putting the thing back together and it doesn't want to turn over.

I even put on an external battery (12.4V) to allow the starter to crank at its maximum potential and nothing... I put some starting fluid in the air box and some down the spark plug hole while the plug was out, when cranking it accelerated, as if it was about to start, and then slowed down again... Did not fire.

In any case, i checked spark again, and thats fine. I also primed the fuel properly for a good 10 seconds of sucking on that vacuum line.

At the end of it all i decided to test if my timing went off again. Tell me if my logic is wrong here:

Pulled out spark plug 1. Looking at the flywheel markings for cylinder top dead centre, i turned the engine manually counter-clockwise until i felt the most compression (cylinder 2 TDC). Throughout the entire compression stroke, the 2T mark did not pass the notch.

Before i open the head again to check timing, can you guys guess at what could have come loose? is it that bolt i am using to turn the engine with?

[n4mwd]

Originally Posted by The_big_dill

Well i spent the day after school putting the thing back together and it doesn't want to turn over.

I even put on an external battery (12.4V) to allow the starter to crank at its maximum potential and nothing... I put some starting fluid in the air box and some down the spark plug hole while the plug was out, when cranking it accelerated, as if it was about to start, and then slowed down again... Did not fire.

In any case, i checked spark again, and thats fine. I also primed the fuel properly for a good 10 seconds of sucking on that vacuum line.

At the end of it all i decided to test if my timing went off again. Tell me if my logic is wrong here:

Pulled out spark plug 1. Looking at the flywheel markings for cylinder top dead centre, i turned the engine manually counter-clockwise until i felt the most compression (cylinder 2 TDC). Throughout the entire compression stroke, the 2T mark did not pass the notch.

Before i open the head again to check timing, can you guys guess at what could have come loose? is it that bolt i am using to turn the engine with?

This is strange. Didn't you say it ran fine before the valve adjustment? If its not turning over, then the valves are hitting the pistons. Did you make two full revolutions by turning the crank bolt?

If you turn the nut clockwise, it should not loosen the nut. It will loosen only if you turn it counter-clockwise. I was thinking it should also be possible to check the flywheel by using the screwdriver in the spark plug hole that you mentioned earlier. You can tell where TDC is with how high the piston is and then the mark should be right there in the view hole.

IF the nut is only loose and the key is not sheared, it only needs to be torqued and you can do that just be putting it in gear and having someone hold the brakes. The torque is 50 ft-lbs not Newtons.

[The_big_dill]

Originally Posted by n4mwd

This is strange. Didn't you say it ran fine before the valve adjustment? If its not turning over, then the valves are hitting the pistons. Did you make two full revolutions by turning the crank bolt?

If you turn the nut clockwise, it should not loosen the nut. It will loosen only if you turn it counter-clockwise. I was thinking it should also be possible to check the flywheel by using the screwdriver in the spark plug hole that you mentioned earlier. You can tell where TDC is with how high the piston is and then the mark should be right there in the view hole.

IF the nut is only loose and the key is not sheared, it only needs to be torqued and you can do that just be putting it in gear and having someone hold the brakes. The torque is 50 ft-lbs not Newtons.

Yes, it ran before the valve adjustment and after the first one, its when I thought my timing was off that everything went downhill.

Admittedly, I always turned the flywheel counter clockwise to avoid jumping teeth with the cam chain. Unfortunately, as I originally got the timing wrong, at one point when valves were coming in contact with pistons, I was turning counterclockwise pretty hard, without realizing what was happening, to the point where the chain jumped a few teeth.

Furthermore, I completely agree with you that logically, if the timing is off, valves should be hitting pistons, but I do not feel this interference and neither does the starter.

Maybe it is hitting, but since something is loose, like the flywheel bolt, it is just spinning to the point of least resistance, and from then on doesn't work. But then again, if it started with the starting fluid, then it had no resistance in the first place.

Finally, whoever designed the airbox boots needs to be smacked.
Posted via Mobile Device

[Motofool]

Originally Posted by The_big_dill

............At the end of it all i decided to test if my timing went off again. Tell me if my logic is wrong here:

Pulled out spark plug 1. Looking at the flywheel markings for cylinder top dead centre, i turned the engine manually counter-clockwise until i felt the most compression (cylinder 2 TDC). Throughout the entire compression stroke, the 2T mark did not pass the notch.

Before i open the head again to check timing, can you guys guess at what could have come loose? is it that bolt i am using to turn the engine with?

Piston #2 is moving up while all valves are closed, creating compression resistance.
2T mark not showing up means pick up coil has no reason to command a spark in #2 10 degrees before top dead center position, as it should.



Again, sparks and valves may be out of synchronicity for both cylinders; if so, engine cannot fire; which was the reasoning behind my previous post.

The connection between the generator and the crankshaft is via friction created between their two conical surfaces and the central nut.
There is key that keeps the rotational position of both parts fixed.
If the central nuts is loose, friction between the cones is reduced but that key keep both parts from rotating respect to each other.
If the engine keeps working with that loose nut, the pulsations may shear that key off, allowing the generator and timing pick-up coil rotate freely, causing the engine to stop.

We cannot know if the above happened to your engine, but I am inclined to believe that the valves are the ones out of proper timing respect to the sparks, since those are the parts that you have worked with.
If the nut is loose, I don't think that you would have been able to turn the engine counter-clockwise, let alone to shear that key manually.

If I am correct and the valves are off due to the chronic slack in the cam chain, you will need to find a permanent solution to that dangerous condition that could destroy the engine without warning at the worse moment.

If I were you, I would do the following now:
1) Put that poor battery on a slow charger.
2) Verify that the pistons are not hitting the valves: remove both spark plugs and gently rotate the rear tire with the gear in first and the bike on the center stand.
3) Verify that the sparks are happening a few degrees before the piston reaches the top (use a wood rod rather than a screwdriver and remove the tank for easier access).
4) Verify that, for that position of the piston, all valves are closed (I would open the top to see the position of the cams), even doing some leak-down test.
5) If 3 and 4 above give negative results, I would open the top and the left cover to make whatever is needed to make those three things match: position of piston, closing of valves and position of pick-up coil/magnetic dot on generator surface.

I feel sorry for all the frustration that you have endured.

[The_big_dill]

Originally Posted by Motofool

Piston #2 is moving up while all valves are closed, creating compression resistance.
2T mark not showing up means pick up coil has no reason to command a spark in #2 10 degrees before top dead center position, as it should.



Again, sparks and valves may be out of synchronicity for both cylinders; if so, engine cannot fire; which was the reasoning behind my previous post.

The connection between the generator and the crankshaft is via friction created between their two conical surfaces and the central nut.
There is key that keeps the rotational position of both parts fixed.
If the central nuts is loose, friction between the cones is reduced but that key keep both parts from rotating respect to each other.
If the engine keeps working with that loose nut, the pulsations may shear that key off, allowing the generator and timing pick-up coil rotate freely, causing the engine to stop.

We cannot know if the above happened to your engine, but I am inclined to believe that the valves are the ones out of proper timing respect to the sparks, since those are the parts that you have worked with.
If the nut is loose, I don't think that you would have been able to turn the engine counter-clockwise, let alone to shear that key manually.

If I am correct and the valves are off due to the chronic slack in the cam chain, you will need to find a permanent solution to that dangerous condition that could destroy the engine without warning at the worse moment.

If I were you, I would do the following now:
1) Put that poor battery on a slow charger.
2) Verify that the pistons are not hitting the valves: remove both spark plugs and gently rotate the rear tire with the gear in first and the bike on the center stand.
3) Verify that the sparks are happening a few degrees before the piston reaches the top (use a wood rod rather than a screwdriver and remove the tank for easier access).
4) Verify that, for that position of the piston, all valves are closed (I would open the top to see the position of the cams), even doing some leak-down test.
5) If 3 and 4 above give negative results, I would open the top and the left cover to make whatever is needed to make those three things match: position of piston, closing of valves and position of pick-up coil/magnetic dot on generator surface.

I feel sorry for all the frustration that you have endured.

Thank you once again with the details, your description makes sense, and thanks for your sympathy.

I have no problem taking the valve cover off again, so long as I don't have to touch the carbs. The good news of all of this is that I can pretty much do a valve adjustmment with my eyes closed.

Will I be able to see a spark at such low engine revs of only spinning the rear tire by hand?

I will try to set some time aside today to see if my timing really went off and I will get back to you guys. Hopefully I can get this all figured out soon.
Posted via Mobile Device

[n4mwd]

Yes, use a wooden dowel not a screwdriver. A new pencil would probably do just fine.

While I did mention the possibility of a flywheel sheer, it is a very remote possibility - so I recommend that you don't spend a lot of time on that aspect.

The valves are what you touched and that is where the problem most probably lies. However, it seems you also discovered a potential cam chain failure which, if you had ignored it, would have eventually destroyed the engine.

I think at this point, once you are satisfied with the flywheel bolt, it may be time to pull the clutch cover and take a close look at the tensioner mechanism. If you do, you will need a new clutch cover gasket and a way to remove the old one that doesn't involve using anything made of metal. Metal damages the facings. Of course, the oil must also be drained. If its new, you can reuse it.

Also, the chain should not be skipping teeth if the upper chain guard is there. They can't get over the tooth.

And be forewarned that if the chain is bad, its a major job to change it.

[The_big_dill]

So i gave up and sold the bike...

[The_big_dill]

OR did i?

http://youtu.be/03TgvWJxW7A

Correction in the video, i meant to say "n4mwd"

[n4mwd]

Did you ever get it running again?

Its a shame you gave up. I think you would have benefited from having a pro do a diagnostic for you. If I was there in person, I could probably figure it out pretty quick. Its just not very easy to see things, even with video, when you aren't there in person.

[The_big_dill]

Originally Posted by n4mwd

Did you ever get it running again?

Its a shame you gave up. I think you would have benefited from having a pro do a diagnostic for you. If I was there in person, I could probably figure it out pretty quick. Its just not very easy to see things, even with video, when you aren't there in person.

No i didn't, you just got to the thread before i can post another post XD

[n4mwd]

OK, I see you were being sarcastic. Glad to see it running. Sounds good too. The ticking sounds a lot like clutch basket ticking to me. Did you test it?

What about your cam chain? Did you figure out why it was so loose? It shouldn't be run if its too loose.

[n4mwd]

The bike looks so different from the regular pregen. I keep forgetting that you actually have the pre-pregen.

[The_big_dill]

Originally Posted by n4mwd

OK, I see you were being sarcastic. Glad to see it running. Sounds good too. The ticking sounds a lot like clutch basket ticking to me. Did you test it?

What about your cam chain? Did you figure out why it was so loose? It shouldn't be run if its too loose.

When i pull in the clutch lever, some of that knocking/ticking goes away. But most of the ticking is from the top right side of the engine, where the cam chain sits.

It is definitely not tight, but it is only that was when cylinder 2 is at TDC.

The guides were fine, the chain tensioner mechanism was moving smoothly when i was done with it and the CCT itself was alright (i asked a pro) and also replaced the spring inside the CCT just for good measure. Only thing left is the chain i would say :\

I think thats a job for the winter to be honest with you, at this point i am going to ride it down to school until November or something and then store it away.

[The_big_dill]

Originally Posted by n4mwd

The bike looks so different from the regular pregen. I keep forgetting that you actually have the pre-pregen.

Haha, i have learned a thing or two from the Wiki, but sometimes i have to figure it out or refer to the manual as it isn't the same.

For example, the ninja 250 wiki says that the chain on all bikes 86-mid 2000's is 106 links long, whereas this pre pregen has 104 links.

The other difference is my front rotor is on the opposite side of the front wheel, or i should say your rotor is on the opposite side

Those are just 2 things off the top of my head.

[n4mwd]

Considering its age, maybe a good plan would be to ride it until the engine blows and then just buy a pregen engine and bolt it on there. They can be bought for around $500 if you keep an eye on ebay. I'm not sure about shipping up there though.

[The_big_dill]

Originally Posted by n4mwd

Considering its age, maybe a good plan would be to ride it until the engine blows and then just buy a pregen engine and bolt it on there. They can be bought for around $500 if you keep an eye on ebay. I'm not sure about shipping up there though.

I have always thought of a replacement engine as a back up option, but i think i would rather do a rebuild with a new chain and sprockets.

[Nemesis]

Who wants to do my valve adjustment for me? I'll pay you for your service. LMK.

[n4mwd]

Originally Posted by The_big_dill

I have always thought of a replacement engine as a back up option, but i think i would rather do a rebuild with a new chain and sprockets.

The cam sprockets and chain are identical to the pregen. So you can probably buy a new set of cams on ebay pretty cheap. Then a new chain from the dealer. The cams are a little different, but I think the new ones are just ground better.

Still, you have to wonder just why your chain stretched. If it stretched.

When you start into it this winter, pull off the clutch cover and see if the chain guard is still around the chain where it goes around the crankshaft. If its not there, it means that at some point, someone overtorqued the rockers and destroyed the engine. Part of the problem is that it stretches the cam chain and breaks that guide off. Another thing is that without the guide there, the cam chain is going to be a little floppy.

The good thing is that it also means that you wont have to split the engine to change the cam chain if the guide isn't there.

[The_big_dill]

Originally Posted by n4mwd

The cam sprockets and chain are identical to the pregen. So you can probably buy a new set of cams on ebay pretty cheap. Then a new chain from the dealer. The cams are a little different, but I think the new ones are just ground better.

Still, you have to wonder just why your chain stretched. If it stretched.

When you start into it this winter, pull off the clutch cover and see if the chain guard is still around the chain where it goes around the crankshaft. If its not there, it means that at some point, someone overtorqued the rockers and destroyed the engine. Part of the problem is that it stretches the cam chain and breaks that guide off. Another thing is that without the guide there, the cam chain is going to be a little floppy.

The good thing is that it also means that you wont have to split the engine to change the cam chain if the guide isn't there.

Good info, but if i am going to take the cylinder head off, i might as well do a full engine rebuild, dont you think?

Also, Why would i change the cams?

If i am getting a new chain, i have to get new sprokets, no two ways about that.

The bike has always been this way, I don't know if i mentioned it to you before, but i am the 15th owner on this beauty.

I see many half ass jobs done all around the bike. Missing bolts, dented tank, fairings were repaired, but what got me the most was that the idle mixture screw cylinder was just glued on, it wasn't sturdy, it was moving around... I took it off and JB welded it, hold much better now.

[n4mwd]

Originally Posted by The_big_dill

Good info, but if i am going to take the cylinder head off, i might as well do a full engine rebuild, dont you think?

With 15 owners its a good chance that it was abused so a complete rebuild might be worthwhile. But not cost effective just so you know. I bought a 2007 pregen last summer for $500 and it was in worse shape than yours. Long story short, it cost me about $600 to rebuild the engine. But there is also the learning experience value.

Also, Why would i change the cams?

Better, stronger, faster.

If i am getting a new chain, i have to get new sprokets, no two ways about that.

Not a bad idea. However, you can't really change the sprocket on the crankshaft.

what got me the most was that the idle mixture screw cylinder was just glued on, it wasn't sturdy, it was moving around... I took it off and JB welded it, hold much better now.

Idle mix screw on the carbs? It just screws in, why JB-weld it?

[The_big_dill]

Originally Posted by n4mwd

With 15 owners its a good chance that it was abused so a complete rebuild might be worthwhile. But not cost effective just so you know. I bought a 2007 pregen last summer for $500 and it was in worse shape than yours. Long story short, it cost me about $600 to rebuild the engine. But there is also the learning experience value.

Better, stronger, faster.

Not a bad idea. However, you can't really change the sprocket on the crankshaft.

Idle mix screw on the carbs? It just screws in, why JB-weld it?

I tend to care more about the experience than the money

So do people typically change the cam chain without changing the sprockets? From experience, thats a nono.

The idle mixture screw sits in a little cylinder which has the thread for the idle mixture screw, that part literally broke off:

[Motofool]

Originally Posted by The_big_dill

OR did i?

http://youtu.be/03TgvWJxW7A

Correction in the video, i meant to say "n4mwd"

You are every welcome, Phil

I have been very happy hearing the exhaust notes of that beauty.

Now, may I ask how did you make it happen?

[n4mwd]

Originally Posted by The_big_dill

So do people typically change the cam chain without changing the sprockets? From experience, thats a nono.

The idle mixture screw sits in a little cylinder which has the thread for the idle mixture screw, that part literally broke off:

That's nuts. How on earth did they do that? Drop it maybe? Target practice?
Anyhow, the engine sounds really good, so the carbs seem fine as long as it doesn't come loose.

It makes total sense to change the cam sprockets when you change the chain. I've never heard of it done on a Ninja, but its common practice with other engines.

[The_big_dill]

Originally Posted by Motofool

You are every welcome, Phil

I have been very happy hearing the exhaust notes of that beauty.

Now, may I ask how did you make it happen?

Very good question, and i was wondering that myself.

What happened was that when i checked the timing, everything was synchronized, which kinda upset me as i was at a dead end. Next what i did was that while i had the valve cover off, i put some starting fluid down the spark plug hole. I then put the plugs back in place and loosely attached the ignition coils to the frame. I went to crank and nothing. Put the spare car battery to crank and still nothing. At my disappointment i kept cranking it for a good 10 seconds (i never go over 4-5 as its no good for the starter), at which point i started hearing that the cranking is getting easier/faster, so i gave her a break. Then went to crank again, and she finally started... WITH THE VALVE COVER OFF!

Although oil went everywhere, i was kinda happy that the bike finally started
i turned it off quickly and wanted to see if that was just the starting fluid, and this time it ran a bit better, but now everything was covered in oil, lol.

Over the several times i took it apart and put it back together i cleaned all the surfaces where the cam and cam caps sit. But this is the only thing that comes to mind, and is a very unlikely reason why it did not start.

Originally Posted by n4mwd

That's nuts. How on earth did they do that? Drop it maybe? Target practice?
Anyhow, the engine sounds really good, so the carbs seem fine as long as it doesn't come loose.

It makes total sense to change the cam sprockets when you change the chain. I've never heard of it done on a Ninja, but its common practice with other engines.

Your guess is as good as mine, only they fixed it with some glue that was very rubberized.

I am glad to hear it from the pros

If only the ticking disappeared... Wishful thinking i guess :\

Have you ever heard long time results of a ninja with a new cam chain?

[Motofool]

Originally Posted by The_big_dill

...............Then went to crank again, and she finally started... WITH THE VALVE COVER OFF!

Although oil went everywhere, i was kinda happy that the bike finally started................

I only can imagine your surprise !!!

I hope she will roll over many many more miles.

[n4mwd]

Originally Posted by The_big_dill

At my disappointment i kept cranking it for a good 10 seconds (i never go over 4-5 as its no good for the starter), at which point i started hearing that the cranking is getting easier/faster, so i gave her a break. Then went to crank again, and she finally started... WITH THE VALVE COVER OFF!

That is a symptom of the carb bowls not getting full. As you crank, a vacuum gets applied to the petcock and allows the gas to flow. More cranking means more flow. When you finally got enough gas in there, it started.

Your guess is as good as mine, only they fixed it with some glue that was very rubberized.

I've seen that stuff before. Its regular epoxy. JB-Weld is also epoxy, but its better stuff.

Have you ever heard long time results of a ninja with a new cam chain?

No, I have never heard of anyone actually replacing the cam chain on a Ninja. I guess its because its such a big deal to replace it.

[The_big_dill]

Originally Posted by n4mwd

That is a symptom of the carb bowls not getting full. As you crank, a vacuum gets applied to the petcock and allows the gas to flow. More cranking means more flow. When you finally got enough gas in there, it started.

I would imagine so, but I primed the carbs pretty well for a good 10 seconds. I had the fuel line off the petcock the first time I primed and got fuel everywhere lol.
Posted via Mobile Device

[n4mwd]

Originally Posted by The_big_dill

I would imagine so, but I primed the carbs pretty well for a good 10 seconds. I had the fuel line off the petcock the first time I primed and got fuel everywhere lol.
Posted via Mobile Device

It needs to run into the carbs. Alternatively, I have seen some guys hook a funnel directly to the carb gas line and literally pour it in.

Anyhow, now its time to take it out and ride it while you still can before winter. It would be nice to know if the bike performs well above 5500 rpm because that's where the primary jets usually kick in.

[The_big_dill]

Originally Posted by n4mwd

It needs to run into the carbs. Alternatively, I have seen some guys hook a funnel directly to the carb gas line and literally pour it in.

Anyhow, now its time to take it out and ride it while you still can before winter. It would be nice to know if the bike performs well above 5500 rpm because that's where the primary jets usually kick in.

I rode the bike to school and back today (~80km).

The bike pulls much harder than it use to across the entire rev range, primarily in the low RPM. It has plenty of power the whole time, so long as i am not in 1st lol, it feels really empty when i pass 4k rpm in first.

Towards the end of the day, as i was going home, i started hearing some sluggishness in the valves. Hard to describe the noise, but somewhat like a hint of exhaust leak. Also, as soon as i noticed this sound, the bike started starving on power a little bit. I made sure to go easy on the bike the rest of the way, i never went over 6k rpm.

This gives me a good reason to take it apart and see if i messed anything up with the valve adjustment. Will get back with update.

[n4mwd]

I would be curious if you slipped a tooth due to a loose chain. And it wouldn't hurt to check all the rockers to make sure they are all happy. There are two valves per cylinder so if one rocker nut comes loose (not the whole rocker) and the valve stays closed, the engine will still run, but with less power.

[The_big_dill]

So i took it all apart again and everything looks normal.

Timing was fine.

I re-adjusted the valves a little bit. And as before, the intake screw is as far out as it can go... I remember looking at it when it was out and the screw is bottomed out against the rocker. The only good news is that this intake rocker is barely meeting the wider clearance spec. Only 1 rocker is doing this.

I re-torqued all of the rocker nuts to 14.2 ft lbs. just to leave a bit of marginal error of the torque wrench.

As i was adjusting the valves, i happen to notice the chain had different amounts of tension as i would rotate the crank. This makes sense as the cams are engaging the rockers and putting tension on the chain, but at one point it was very loose!


Other points it was fairly tight:


Also, look at this intake valve spring:


Whats that white crap on it? Not all springs have that, only a few.

I tried measuring the chain again and i am getting stupid numbers, and yes, i did tension it when measuring. One of the numbers i did get was 1.9cm/3 rivets = 126.67mm/20 rivets.

[Motofool]

You need a measurement instrument able to show you tenths of millimeter.
You can measure 14 links on that horizontal line when under tension.
The dimension should be between 88.9 and 90.2 mm.

However, the slack is still excessive and could be the only source of the noises.

[The_big_dill]

Originally Posted by Motofool

You need a measurement instrument able to show you tenths of millimeter.
You can measure 14 links on that horizontal line when under tension.
The dimension should be between 88.9 and 90.2 mm.

However, the slack is still excessive and could be the only source of the noises.

Which brings me to another question, where in the cam path does it slap to give that sound? is it at the top chain guide? i am assuming so because thats where the noise is the loudest.

Anything regarding the valve spring?

And most importantly, why is the rocker screw bottoming out?

[n4mwd]

Originally Posted by The_big_dill

Which brings me to another question, where in the cam path does it slap to give that sound? is it at the top chain guide? i am assuming so because thats where the noise is the loudest.

Anything regarding the valve spring?

And most importantly, why is the rocker screw bottoming out?

Valve spring: Its too hard to tell in the photo. But probably just some paint the mfg put on there.

Rocker: The rocker screw may be broken. I would remove it and examine both it and its seat. Its very unusual for a screw to tighten up like that - especially with a locknut holding it.

[Motofool]

Originally Posted by The_big_dill

Which brings me to another question, where in the cam path does it slap to give that sound? is it at the top chain guide? i am assuming so because thats where the noise is the loudest.

Anything regarding the valve spring?

And most importantly, why is the rocker screw bottoming out?

Once the chain is loose, everything produces noise: the top guard, the sprockets, the guides and even the CCT.

I assume that paint is some form of identification; maybe someone worked in that area before you bought the bike.

Same for the rocker screw, it may be a substitute; but I would leave it alone if it is doing its function so far.

My priority would be find a way to keep that chain under tension at all times, anything else is secondary because, as has been explained earlier, jumping teeth and losing the valve's timing at high rpms' would be a catastrophe.

Could you measure the chain with 0.10 mm precision?