Cam timing on a Cb125t

**boostin** · 21st February 2008, 22:47

How do I do the timing on a Cb125t ?

There are two dots on the cam chain wheel on opp sides. These are the only marks I can see to use...where should they be at tdc?

Thanks.

**quallman1234** · 21st February 2008, 22:52

Sully taught me this just the other day, He know's exactly how to do it.

I would tell you from memory but i might of forgetten something!.

Sully's the man for this.

**diesel pig** · 21st February 2008, 22:53

which motor do you have? the early silver painted motor or the late Black painted motor?

**boostin** · 21st February 2008, 22:58

Originally Posted by diesel pig

which motor do you have? the early silver painted motor or the late Black painted motor?

It is silver as far as I can see but may have changed colour over its lifetime? just picked it up the other week, it had a dropped valve so I wasn't the one that took it apart.

**xwhatsit** · 21st February 2008, 23:05

I would think that those dots should line up with the valve cover gasket face. It doesn't matter which way it's up -- the ignition system will probably be `wasted spark', so it doesn't matter if it's 180-degrees out.

**boostin** · 21st February 2008, 23:07

Originally Posted by xerxesdaphat

I would think that those dots should line up with the valve cover gasket face. It doesn't matter which way it's up -- the ignition system will probably be `wasted spark', so it doesn't matter if it's 180-degrees out.

Thanks that is what I suspected. Means I need to increase the base spacer to stop the valves hitting...

**Sully60** · 23rd February 2008, 12:23

It does matter

You need to have #1 (left)cylinder at TDC. Pic 1

The dots on the chain wheel should by level with the gasket surface. If the dots don't seem to do this perfectly make sure the front dot is lower. When the camcahin tensioner is released the chainn wheel will move clockwise and line up with the gasket surface better

The camshaft has a square notch in end your looking at, this should be towards the rear of the engine. Pic 2 (sorry I couldn't find the chainweel to put on in that picture)

**xwhatsit** · 23rd February 2008, 12:41

Oh shit -- this is a twin

Never mind me.

**boostin** · 23rd February 2008, 12:48

Originally Posted by Sully60

It does matter

You need to have #1 (left)cylinder at TDC. Pic 1

The dots on the chain wheel should by level with the gasket surface. If the dots don't seem to do this perfectly make sure the front dot is lower. When the camcahin tensioner is released the chainn wheel will move clockwise and line up with the gasket surface better

The camshaft has a square notch in end your looking at, this should be towards the rear of the engine. Pic 2 (sorry I couldn't find the chainweel to put on in that picture)

Cool thanks for that, I managed to get it all sorted in the end.