Zongshen timing chain

[SpudRider]

Originally Posted by NW1

Mabey before i replace the ASST i can get tdc on the spare engine and check its cam sprocket markings and repeat them on the engine i'm fixing.

Yes, that is exactly what I recommend.

[NW1]

Originally Posted by Weldangrind

A CB200, like HB says. The XR is a different length. Use Google Chrome and visit www.taobao.com. Search for CB200 and then filter motorcycle parts.

The cam chain may be the same bt i dont see this engine being a CB200 clone, search google cb200 picture.

[NW1]

From the spare motor

[SpudRider]

Originally Posted by NW1

From the spare motor

The above image seems to indicate the flywheel in the image below is close to top dead center (TDC).



Is there a mark on the cylinder head which shows how the hash marks on the cam sprocket should align?

[NW1]

The marks, - , on each side of the cam sprocket allign with the bottom of the top section of the head, the top gasket, perfectly. I cant see any marks relating to the marks on the flywheel.

[NW1]

Obv with the cam sprocket dot pointing down

[SpudRider]

Originally Posted by NW1

The marks, - , on each side of the cam sprocket allign with the bottom of the top section of the head, the top gasket, perfectly. I cant see any marks relating to the marks on the flywheel.

You need to observe the TDC mark on the flywheel through the inspection hole of the left crankcase cover.

What makes you think something is wrong with the cam chain?

[NW1]

Ok, inspection hole.

At the start of this thread i thought the cam chain had snapped bt we discovered the tensioner was faulty.
This part of the thread is only concerned with lining the flywheel cog and the cam cog on the cam chain correctly before i install my spare tensioner.
The flywheel rotates without moving the cam chain if there is no tensioner.

[SpudRider]

Have you removed the automatic, cam chain tensioner (ACCT) and inspected it as I recommended? If so, how did you inspect it?

[NW1]

Originally Posted by NW1

The cause.
I've got one in my spare motor

This is the tensioner, im now installing one from my spare motor

[NW1]

Photo in post #28

[SpudRider]

Okay, looking at the photograph in post #28, it seems the old ACCT is broken. It is well you have a spare ACCT.

Before I describe how to fix your problem, I need to know how much you understand regarding camshaft timing. Do you know how to inspect and adjust the valve clearances for your motorcycle?

[NW1]

No

[NW1]

Well ive done them on my huang shen 49cc.

The valves were good before how can the temsioner spring snapping alter them ?

[SpudRider]

Originally Posted by NW1

Well ive done them on my huang shen 49cc.

The valves were good before how can the temsioner spring snapping alter them ?

That's exactly my point. A damaged cam chain tensioner probably will not alter the cam chain timing, unless the cam chain skipped a tooth on the cam sprocket. However, you won't know for sure whether things are well unless you know how to check the valve clearances.

I suggest you read the following threads to learn the procedure for checking the valve lash/clearances.

http://www.chinariders.net/showthread.php?t=977
http://www.chinariders.net/showthread.php?t=4539

After you are familiar with that procedure, you need to correctly install your spare ACCT. After the ACCT is correctly installed, check the valve clearances. If everything checks out properly, you are in good shape, and you can ride your motorcycle.