Timing marks

[chassisbuilder]

I have a concern with the timing marks on my 2005 450R.
I have had the head off of this bike. When I line up the correct timing marks on the crank and engine case, the piston is about an inch away from TDC. Even though the manual says that when the dimple on the crank and the mark on the case align, that this should be TDC. What is the deal here?
If I actually place the piston on TDC there is a white paint mark on the crank that lines up with the marking on the engine case, but nothing is mentioned of this in the manual.
So what mark should I trust? Has anyone had any experience with this?
I went by my local dealer yesterday, and one of the mechanics there told me to ingnore what the manual says and to place the piston @ TDC and then install the cylinder head and then make sure my cam sprocket marks line up with the corresponding marks on the cylinder head. To be honest, that makes the most sense to me, but I can't understand why the manual would tell you one thing, and it not be right, not to mention that the marks are there for a reason.

Any help or advise will be greatly appreciated,

Thanks,

Craig Sheffield

They should both line up at the same time. The 2 on the crank and the cam. The guy @ the dealer is a retard.

[chassisbuilder]

Originally posted by TRX450R_Racer
They should both line up at the same time. The 2 on the crank and the cam. The guy @ the dealer is a retard.

Then why is it that when the dimple on the crank and the mark on the case align, the piston isn't @ TDC. its about an inch away?

Is this correct?

Did you spin it another turn. You might be off by a stroke.

I never noticed where the piston stops when you aren't on the compression stroke....................but I do know from putting together so many motors that they should both line up.

[chassisbuilder]

Originally posted by TRX450R_Racer
Did you spin it another turn. You might be off by a stroke.

I never noticed where the piston stop when you aren't on the compression stroke....................but I do know from putting together so many motors that they should both line up.

With the head off, it wouldn't matter what stroke it was on, Right?
Not until the cylinder head is installed and the cam on the correct way is compression and exhaust stroke going to have any effect.

But back to what you said. I can roll the motor over numerous times, and still end up in the same place. I have built many automotive engines in the past, but this being my first ATV. The TDC thing is puzzling me. My understanding is that when you are asked to place the engine on TDC using the designated timing marks, then your piston should be @ TDC.

[chassisbuilder]

by the way, thanks for your time and help.

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.

[chassisbuilder]

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.

That is good information, I will have to check that thoery. Makes sense.

Thanks again.

[Nick110]

How to I make sure that it is on the correct stroke? My quad wont start and I know its a timing issue. I lined up the dimples for the crank and then on the cam gear too. But it wont start, only pops every 1 outa 30 kicks.

If the marks line up it is on the correct stroke. Are your valve clearances correct? If the valves are good you might be off 180 degrees. When it is at top dead center on the compression stroke the cam lobs will be pointing towards the back of the quad and all of the valves should be closed with no pressure on them.

[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.

http://i44.photobucket.com/albums/f29/nick110/DSCF0322.jpg

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.

http://i44.photobucket.com/albums/f29/nick110/DSCF0322.jpg

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

[Nick110]

Originally posted by chassisbuilder
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

its lined up with the dimple.

And it wont bump either. The motor does sound louder than normal. Like a ticking.

Do you have spark, fuel and compression?

[Nick110]

Has spark, fuel, but I dont have a comp. tester but it is pumping out of the exhaust.

[450rJam]

sounds like timing is still off

mine has a demple and a hole, the first time I adjusted the valves it was a bit confusing which to use (demple) but mine is 06

the piston hits the top of its stroke on every stroke

you just have to time the cam/spark correct

[Nick110]

According to the picture I posted I have the dimple on the crank lined up with the mark on the outer case, and then the 2 dimples on the cam gear are both lined up with the arrows on the cam tower. This is correct?

Originally posted by Nick110
According to the picture I posted I have the dimple on the crank lined up with the mark on the outer case, and then the 2 dimples on the cam gear are both lined up with the arrows on the cam tower. This is correct?

Yes

[FoxMxRiders]

When you rebuild the engine,just put the piston tdc and put the cam with the mark lined up with the case.

The engine doesn't have a specified stroke when the cam is off.The cam choose which stroke your are.

[pro-rider46]

Originally posted by Nick110
According to the picture I posted I have the dimple on the crank lined up with the mark on the outer case, and then the 2 dimples on the cam gear are both lined up with the arrows on the cam tower. This is correct?

have you tried putting the crank to where the white mark lines up with the arrow on the case, that might be a lil better, also if you want, you can pull off the head and see where the piston is really at top dead center, then you will know if the dimple is right or not, i did that when i put my engine together.

try that and let us know how it went.
-Steve