Timing questions.....

[willjoe86]

Alright-Im rebuilding my 250x and right now Im trying to get the timing set

When you turn the crankshaft to get it to TDC(top dead center) the manual says that its supposed to be in the compression stroke-How do I know if its on the compression stroke or not?

I did try to do it, but after lining it all up and bolting the sprocket to the camshaft, I turned it around a few times and lined it up to the "T" notch on the flywheel-however, the sprocket notches wouldnt line up.

Also, when lining up the "T" notch, is it supposed to stay there fairly easily or do you have to hold it there?

I dont know whats wrong-maybe I just dont get this whole timing thing, but it would help if someone could explain it to me.
Thanks a lot!
Will

[cals400ex]

i am not sure on the 250 but this is how it is on a 400ex. align the t-mark on the flywheel before you put your cam in. put the cam in(lobes facing down) and align the sprocket in the timing chain so that the two marks on the sprocket align with the top of the head. there is probally another line on the top of the sprocket telling you which side is the top of the sprocket and which side of the sprocket faces down. the compression stroke should not matter until you have the camshaft installed. i found it easiest for myself to align the t-mark first. then i put the sprocket onto the chain so that the two lines on the sprocket aligned with the top of the head. i then slid the cam through the cam sprocket. when your on the compression stroke, your exhaust valves will be loose, not tight. you should not have to hold the flywheel in place. it should stay there fairly well. with some effort, yes, it will move. good luck

[ghak99]

I just went through this same problem. I had to put my x in gear in order for the flywheel to stay where i needed it to. After I bought a new cam chain it went together the first try. My chain was very stretched so you might check that first.
Hope this helps