Hey everyone. New to the forum. I have a tao 125 motor that I am rebuilding. I’m currently working on setting the timing up. When I find the mark on the flywheel at top dead center, the piston is about 1/4 inch below the very top of jug. Is this normal for this type of motor or is something else going on that I don’t see? I figured maybe the manufacturer marked it wrong but I’m not sure. I spun the crank multiplied times and still doesn’t align up. From what I know, the piston should be seared all the way up at tdc. Thoughts?

 

Are you doing top end or complete rebuild? What happen to engine?

 

So it was given to me by a friend and someone dove into it and quit the project so I inherited it. The bottom end turns nicely, no scoring on the walls and the piston head looks good. I bought a new pre assembled head for it. But the timing doesn seem to add up in my mind. If that makes sense.

 

is camshaft and gear different then OEM?

 

An rule of the thrumb align flywheel keyway straight to the camshaft gear lines? have you done this if so how much was the line off?That would be top dead center

 

On some flywheels there should be two marks, one for TDC, usually marked T and another, which may well be 1/4" before TDC for spark timing, usually marked F. Many modern engines don't have an F mark as the spark timing is "fixed" on them anyway. However the most likely cause of your problem is a slipped flywheel, so the flywheel is no longer on it's key. Best to check this by removing and inspecting for a broken or missing key.

 

It was off about 1/2 or so past the T mark when spinning counterclockwise. The head is identical to the original. Same everything from what I see.

I’ll inspect the flywheel and see if there’s anything going on there. I took the cover off and just peeked in there but didn’t see anything obvious. I’ll check again.

 

Alot of timing is off 1/2 tooth