Sierra-Striking noise in engine head ?!

[azriel]

Hi guys!
Just a quick one... :)
Its about Zong Sierra 200...OHC,8500 kms,just serviced before few weeks.

Is it normal for these engines to hear sligtly "striking" noise coming from the engine head? It "strikes" faster when rewing it,but i cant hear it anymore above aprox. 2000 rpms or in driving couse the engine is too loud then.Its strikes a little louder when cold,and after warming up it gets more "metal" sound. Yes, i already adjusted the valves and checked them twice,also checked the camchain and cc tensioner...but will check them again in day or two...

So i think its not a valves tick or a camchain slap sound ,its a little "deeper" sound then that. When i pull the clutch in it still "strikes" , so its not a clutch basket. :?

It starts good when cold ,perfect when hot,does not overheat,runs good for a 200cc,is a little bit lean (will try 132.5 mikuni main)...Im out of ideas with this sound?!
Am i concernd about nothing, or...?

Thanks once again Brothers in bikes !!! :)
Azriel

[FastDoc]

I don't know. Can you post a little video/audio?

[azriel]

Will record it and upload it tomorow after work. :)
I need to open an account on Youtube.
Thanks!

[FastDoc]

I've been able to post videos on Photobucket, if that's easier.

[azriel]

Thanks for the tip Doc!
Its alot easier :D
Ill record it with cold engine and then with warmed up.
I hope it will be hearable on the record.
Thanks one more time! :)

[FastDoc]

No problem. I bet it's nothing. The most likly things would have been cam chain and excessive valve lash both of which appear to have been ruled out already. I don't think being a little lean would have anything to do with it.

[SpudRider]

We eagerly await your video. :) It's normal to hear the valves tap. In the United States we have a saying, "slappy valves are happy valves," meaning it is better to adjust the valves too loose, rather than too tight. ;)

The Zong has an automatic cam chain tensioner, and the Zong camshaft chain is well manufactured, and should not be causing problems with your low mileage. My stock camshaft chain was in good shape when I replaced it at 32,000 miles. :) Based upon your description, I believe you are hearing the normal sound produced by the camshaft rockers tapping the valves. ;)

Spud :)

[azriel]

Well fellas here it is.
You can hear a little cam chain "sizzle" and the other sound that bothers me..
Everything is actually louder on the video. :?
This is with a cold engine,first starting today...when its warmed up it gets about 30% quieter and a little more mettalic.
I completly turned choke off at 00:38.
What do U guys think?


http://i1237.photobucket.com/albums/ff466/cromiro/th_strikingsoundsierra200cc.jpg (http://s1237.photobucket.com/albums/ff466/cromiro/?action=view&current=strikingsoundsierra200cc.mp4)

I converted it from .mov to .avi, but sound remained ok.

Thanks! :)

[Weldangrind]

It might be my laptop speakers, but I don't hear anything unusual. Are you sure that it is coming from the top end? When I'm trying to locate a noise, I put my ear to the handle of a screwdriver and touch the tip of the screwdriver to the engine. As you move the screwdriver around, you'll find the noise.

If the noise is in the top end, you could remove the valve cover to see if everything is ok. Then remove the spark plug and slowly kick the engine over and watch the valves operate. If there is a problem in the top end, you will see it.

[FastDoc]

Best I can tell it sounds normal. Check the tightness of the header bolts though. An exhaust leak can mimick valve noise.

[Weldangrind]

Excellent thought Doc. To expand, I wonder if a leak at the header midpipe would make a similar noise?

[SpudRider]

The engine sounds normal to me; I didn't hear anything terrible. Since you adjusted the valves, and the engine runs great, I don't think you have a problem.

I doubt the exhaust has a loose connection. The Zong exhaust has two pieces; it doesn't have a midpipe. The connection between the exhaust header and the muffler is well sealed, and very robust. :)

Spud :)

[azriel]

W&G,im pretty sure its the top end,but as you all said it sounds normal,i think its then just my imagination hearing the valves tapping and think its something else...i checked the exhaust-its tight. Ill check everything again in few days,if i dont find anything unusual ill just drive it as it is...let them tapp so they can be happy :)

Thank you all for fast & helpful answers!!! :)
Azriel

[Wild_Alaskan]

If its valve noise try adjusting the valves while prying up on the rocker arm with a screw driver so the gap is at its biggest when you use the feeler gauges and adjust.

[azriel]

Thanks for the tip WA, will try that when i check the valves again.-In a day or two... :)
I would be happiest just to hear thunders from my exhaust and nothing else... :lol: :lol: :lol:
Gotta find some cheap aftermarket silencers :D

[2LZ]

Gotta find some cheap aftermarket silencers :D
both Spud and myself are fans of the FMF Turbine Core II. Around a hundred bucks, will bolt eright on, sounds great and also, passes USFS Approval.
I know this may be a stupid question or I may have missed it but when did you last change your oil? As you know, they only hold a quart. I change mine constantly. Cheap insurance.

[azriel]

... when did you last change your oil? As you know, they only hold a quart. I change mine constantly. Cheap insurance.



I changed it before few weeks. Rode it for Aprox. 150-200 kms after oil change.
Indeed-Cheap insurance :)

Ill see if a can get one FMF here in Croatia,the ones from Ebay are a bit expensive for me when you count in shipping and duty,taxes... :?

[azriel]

Well i finally isolated the knocking/striking sound source...
Im amazed how it travels through the engine and can fool you 8O
Actually it is not the top end :oops: :oops: :oops:


http://i1237.photobucket.com/albums/ff466/cromiro/strike.jpg

After checking everything again and again and once again :roll: i realized its definitely coming from this part of the engine (yellow circle) and travels all over the place...on the right side of the engine its also hearable but not so loud as it is here(yellow circle),under the tank its also hearable almost as loud as here(yellow circle) so i thought it was the top end :oops: :oops: :oops:


Final question-could it be normal sound of drivetrain ,or something related to it ,operating and sligtly knocking,so i just take care of oil level (currently im on Valvoline Durablend 10w40 full sinthetic) and service intervals, or maybe a bad bearing somewhere so i need to break in the motor and check everything up? :?

I founded on the tw200 forums that these engines are quite noisy little buggers :)
Thank you all once again on your time helping me out! :)
Azriel

[SpudRider]

...After checking everything again and again and once again :roll: i realized its definitely coming from this part of the engine (yellow circle) and travels all over the place...

Final question-could it be normal sound of drivetrain ,or something related to it ,operating and sligtly knocking...

I founded on the tw200 forums that these engines are quite noisy little buggers :)
Thank you all once again on your time helping me out! :)
Azriel
The only thing under that portion of the left crankcase cover is the countershaft, and the countershaft sprocket.

http://i442.photobucket.com/albums/qq146/spudrider/Crankcase%20Cover/CoverModcloseup.jpg

When the engine is idling, neither the countershaft, nor the drive chain is turning; therefore, you should not hear any noise. ;)

Indeed, these little engines make some noise. I did not hear any unusual sounds when I listened to your video; therefore, I don't think you have any problems with your engine. :)

Spud :)

[azriel]

You are fast Spud! :)
I know that these parts are not turning when idling, just saying that the noise is coming from this portion of the engine,somewhere under the countershaft sprocket,from the inside... :?

[SpudRider]

...I know that these parts are not turning when idling, just saying that the noise is coming from this portion of the engine,somewhere under the countershaft sprocket,from the inside... :?
OK. :) If your engine is running well, and the bike is shifting well, I believe your engine is in good condition. I did not hear any unusual sounds when I listened to your video; therefore, I don't think you have any problems with your engine. ;)

Spud :)

[azriel]

OK. :) If your engine is running well, and the bike is shifting well, I believe your engine is in good condition. I did not hear any unusual sounds when I listened to your video; therefore, I don't think you have any problems with your engine. ;)

Spud :)

OK. Thanks for help Spud! :)

Im new with this kind of bikes (China) and am looking at them with too much care i guess...Ill just start riding it like i stole it :twisted:,changing the oil and service it regulary and stop to worry about these little noisy demons in its engine :lol: :lol: :lol:

I belive they are good little engines and that they will do many kms if you take care for them. 8)

Once again thank you all for great helpful answers!!!

CASE CLOSED :D

[SpudRider]

You're welcome, Azriel. :) Change the engine oil, and clean the oil filter every 1,200 miles (750 Km). Adjust the valve clearances every 2,500 miles (1,500 Km). If you change the oil and adjust the valves regularly, your Zongshen engine will serve you faithfully for many miles. ;)

Spud :)