Timing marks

[dustin_j]

Originally posted by TRX450R_Racer
I'm not 100% sure but I think it does matter. It will only line up properly every 4th stroke...............hence the name 4 stroke.

You're welcome..............always glad to help if I can.

I questioned myself on this same concept when I just rebuilt my 400. The intake and compression strokes mirror the power and exhaust strokes with respect to the piston and crankshaft motion. The valvetrain determine if it is, for example, the intake stroke or the power stroke. You can verify this by turning your flywheel and trying to line it up; every turn will line up the same.

Is there any way that the flywheel could have rotated? Is the key sheared, or not installed? Just some things to think about.

[chassisbuilder]

I just spoke with Craig @CP Customs. He had a 450 engine in house with the head removed. The piston (On his motor) came up to TDC everytime he rotates the crank one full rotation and the dimple and timing mark on the case align, so therefore, my bike has an issue. When I mentioned to him that there was a white paint mark on the crank sprocket that lined up with the timing mark on the case, everytime the piston was indeed @TDC, he seems to think that perhaps the sprocket was stamped wrong and that Honda painted the white mark there identify TDC. (F-up if you ask me)
He also noted that the sprocket can only go on one way, so there is no way that it can be installed wrong. This is the first time this engine has ever been cracked open, and the bike has less than 20 hrs on it.
I don't know what else to do. Besides tearing into the motor more, which I would rather not do.

CraigS

[honda4life72]

on my 05 . it has a white line also and a dimple . but we align with what ever works . the line or dimple lol. and it still runs fine. well the rings didnt seat the first time so....

[Nick110]

Ok just got my quad back from my buddies and I took a look at it. I set the gear to TDC and the lobes are faceing to the back of the quad. The timing marks are lined up. How do I check to see if all of the valves are closed?

Heres what the lobes look like.



Oh I also have the white marks on the gear that you have to line up. They are about a 1/4 inch away from the punch mark.

[ZRider400]

AT TDC of the compression stroke, you want your marks to line up when you lobes are not pushing on the valves at all.

you can tell if they are closed by being able to insert a feeler gauge in between...thatll be good indicator that the valves arent being pushed down/open.

[Nick110]

OK well does that picture look right to you? I can get a feeler guage to check all of the shims, so the valves are closed correct?

Yes it looks good and it looks like the valves are closed.

[Nick110]

OK I just set the valve clearances to spec. and made sure the timing stayed where it was. Then I go to start it and nothing. Wont even pop, just kick, kick, kick, kick, and nothing. Help me guys Im ready to snap someones neck.

Can you bump start it?

[chassisbuilder]

Originally posted by Nick110
Ok just got my quad back from my buddies and I took a look at it. I set the gear to TDC and the lobes are faceing to the back of the quad. The timing marks are lined up. How do I check to see if all of the valves are closed?

Heres what the lobes look like.



Oh I also have the white marks on the gear that you have to line up. They are about a 1/4 inch away from the punch mark.

Nick110, when your cam sprocket marks are lined up with the marks on the head, is the dimple on the cam sprocket lined up with the casing mark or the white paint mark?

Thanks,

CraigS