need some noisy idle help

[TXIN]

My bike making a noise

I realized later I should have tweaked the throttle a time or three, and I know the sound isn't great quality, but does this sound familiar to any of you? It used to run fine, then one day while out on a ride, it got all weird and rough, like an inconsistent miss. I looked around, didn't find anything, rode her again, and it's smooth, but this noise is here now. I've done a valve adjustment, air filter, sparkplugs cleaned and gapped, they looked fine, everything under the valve cover looks fine. The noise isn't quite so bad after she's good and hot, but it's still there, lurking, waiting to make me mad when I start her up next time.

[SteveJ.]

I'm thinkin measure piston heights and/or compression.

http://www.zggtr.org/index.php?topic=276.0


it doesn't sound good.

[TXIN]

I thought the hydrolock was an issue when the bike was sitting, not running down the road?

[Pfloydgad]

Do you have the stock cam chain tensioner on the bike, or a manual tensioner ?
It sounds to me like a cam chain tensioner out of adjustment. Even though the video was on the rt. side of the bike, it sounded like mine did when my tensioner had worked its way loose.
My .02$
RSA, and please, ATGATT.
Greg

[Mettler1]

  Loose cam chain tensioner can cause a pretty loud rattle.  Espcially when cold.

[SteveJ.]

The temporary running rough thing would lead one to guess maybe a hydrolock. Hey, it's free to check it, and to rule it in or out. If it didn't have the rough running part,

it got all weird and rough, like an inconsistent miss

 one would guess maybe starter chain, or loose alt pulley or... The important thing to remember is the word guess.

Diagnosing over the internet is an inexact "science", to say the least. Kinda hard to exactly diagnose an issue  listening to a bunch of rattling coming out of $12 Chinacrap speakers that most computers use. So start ruling some things out, and we can go from there. I would advise against running it until you find the problem and fix it. That is really not a good sound.

Could also be cams jumped time, you will not know until you go in and look, check the lines on the cam sprockets.

[bbroj]

I agree, hard to diagnose from a video. If you have ever done a compression test, doing another now may help determine if cams have skipped tome. But, as mentioned, the best way is to open it and look. Cam chain tensioner is a noisy animal if not adjusted propperly. Forget the idea of the tensioner being "automatic". It would be fractional, but a loose cam chain could vary the cam timing as well and possibly lead to erratic idle. Again, mostly speculation...

[qman]

Judging from the fact that the noise is louder on the left side of the engine and gets quieter once you move to the right side. I would say most definitly that you have a cam chain tensioner problem.

[TXIN]

Okay, so I'll do a piston height, and I definitely want to check the timing chain tensioner. Which one does an 03 have?

[SteveJ.]

hey TXIN,

iff'n you do not have a service and/or Clymer manual, this would be the time to get one

[TXIN]

I had one, but it got ruined over the summer. I've been getting by for now with what I can get on the internets, mainly the COG tech pages, and my previous knowledge. I'm not much for diagnosing new stuff, but I don't forget what I've learned, and I'm pretty mechanically inclined. All engines work in the same basic manner, you gotta get the details for each new one is all.


As for this particular situation, I did an oil change (needed anyway) and removed/inspected the cam chain tensioner. It seems to be in good working order, no bent springs or misaligned anything. I put it back in, and now the original noise is gone, replaced by what is OBVIOUSLY the cam chain smacking into the adjuster at closed throttle, and that new noise goes away with ANY throttle at all. So now I gotta get THAT to stop. 

In this light, it really seems to be the cam chain tensioner. I'm still gonna do the piston height test, but probably not until next week.

[SteveJ.]

I had one, but it got ruined over the summer. I've been getting by for now with what I can get on the internets, mainly the COG tech pages, and my previous knowledge. I'm not much for diagnosing new stuff, but I don't forget what I've learned, and I'm pretty mechanically inclined. All engines work in the same basic manner, you gotta get the details for each new one is all.


As for this particular situation, I did an oil change (needed anyway) and removed/inspected the cam chain tensioner. It seems to be in good working order, no bent springs or misaligned anything. I put it back in, and now the original noise is gone, replaced by what is OBVIOUSLY the cam chain smacking into the adjuster at closed throttle, and that new noise goes away with ANY throttle at all. So now I gotta get THAT to stop. 

In this light, it really seems to be the cam chain tensioner. I'm still gonna do the piston height test, but probably not until next week.

Well those symptoms pretty much put you in the cam tensioner neighborhood. I wouldn't worry about the piston heights at this point as you seem to have it isolated. The running rough part earlier kinda threw me on a tangent.

[bbroj]

At the summer national, I watched and helped as the stock adjuster was adjusted. If you remove it, you can try to carefully pull the center shaft 1 click, it's not easy as it is usually stuck. If you pull it out too far, no worries. Release the "dog" and push it all the way back in. That may loosen it enough to propperly adjust once reinstalled. Still noisy? Loosen the bolts just a bit and tap the back of the adjuster until you hear a click, retighten and fire it up!

[vinny]

It would be for your peace of mind to do the piston height test (hydro lock) - you seem to have tracked down the other issue. Good luck - I hope the test finds everything in good order.

[Gene W]

 It used to run fine, then one day while out on a ride, it got all weird and rough, like an inconsistent miss.
 

Is it still doing this?

The sound in the video sounded like the cam chain adjuster as the other guys already said. However the symptom you described in the quote above sounds like a loose spark plug wire. Make sure all of the contacts are clean and that all four wires are on with a snap.

Gene

[TXIN]

Is it still doing this?

The sound in the video sounded like the cam chain adjuster as the other guys already said. However the symptom you described in the quote above sounds like a loose spark plug wire. Make sure all of the contacts are clean and that all four wires are on with a snap.

Gene

No, it just did it the one time. Never before or again. I'm still working on getting the cam chain adjuster sorted. I had to go to Oklahoma for some training this weekend, so I had to push some things back. Imma get on it this week, though. I think.