[Carolynskiii]

That's it but I just remembered you installed an aftermarket cam which typically don't use decompressors so that's not it lol
Does it rev up and won't move? Like it slipping?
I'm going back to the clutch now but it's weird timing that it would stop working after an oil change unless the old owner used a car oil.

 

[retro]

I just looked at your photos of the timing marks on the sprocket and the flywheel and found your problem.

The camshaft is installed using the wrong mark on the flywheel... you are using the two maximum spark advance marks on the flywheel, when you should be using the Top-Dead-Center (TDC) mark.

There should be a single timing mark on the flywheel labeled "T".
Line up that "T" mark with the mark on the side cover (thru the window where you removed the plug), then install the cam sprocket on the cam so that the sprocket mark is even with the top of the head and snug up the sprocket bolts. Make sure that both cam lobes are facing DOWN when you do this.

Then go back and recheck all of your timing marks for proper alignment (they should match closely). Once you are sure you got it right, tighten up the sprocket bolts, install the chain tensioner and the rocker cover (a thin coating of hondabond or yamabond 4 on the alcohol wiped surfaces) and break it in easy for a bit...

 

[SickNasty]

I just looked at your photos of the timing marks on the sprocket and the flywheel and found your problem.

The camshaft is installed using the wrong mark on the flywheel... you are using the two maximum spark advance marks on the flywheel, when you should be using the Top-Dead-Center (TDC) mark.

There should be a single timing mark on the flywheel labeled "T".
Line up that "T" mark with the mark on the side cover (thru the window where you removed the plug), then install the cam sprocket on the cam so that the sprocket mark is even with the top of the head and snug up the sprocket bolts. Make sure that both cam lobes are facing DOWN when you do this.

Then go back and recheck all of your timing marks for proper alignment (they should match closely). Once you are sure you got it right, tighten up the sprocket bolts, install the chain tensioner and the rocker cover (a thin coating of hondabond or yamabond 4 on the alcohol wiped surfaces) and break it in easy for a bit...

That's the only "T" that I could find. I've checked a few times. There is some dashes then an F and then the T with the line above it. It's in one of the pics that I posted

 

[Carolynskiii]

Hard to tell in the pic but are the lobes totally facing down? They look spun a little to the left.

 

[SickNasty]

Hard to tell in the pic but are the lobes totally facing down? They look spun a little to the left.

Yes they are slightly turned. I thought it seemed weird too...but the sprocket is lined up with the head and it doesn't seem like it could be put on the cam shaft any other way

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[Carolynskiii]

I wish I knew more about the 400ex but it seems your lobes aren't as down facing as the Hot Cam instructions show. I don't know how this can be adjusted or maybe it's possible that they sent you the wrong cam?
Those lobes absolutely need to be down at TDC.

 

[Carolynskiii]

....or maybe you need a new timing chain cause it stretched?

 

[Carolynskiii]

You can't adjust it by losening the sprocket bolts?

 

[retro]

That's the only "T" that I could find. I've checked a few times. There is some dashes then an F and then the T with the line above it. It's in one of the pics that I posted

Use the service manual for this... go through the manual and you'll find photos of the TDC mark on the flywheel. It will be a single line. The way you have it timed in your photo is wrong... you used the ignition advance lines.

Try this... put a socket on the flywheel thru the center plug in the cover and rotate the motor in the normal direction. As you are rotating the motor slowly, watch as the timing marks appear (then disappear) in the window. The first mark(s) you'll see appear are the maximum ignition timing advance marks. continue rotating slowly and the next line(s) to appear are the "F" (Fire) initial ignition timing mark. Continue slowly and the final mark to appear will be the TDC mark. Use that mark... and use the service manual photos to show you the proper procedure. You can screw up by lining up the marks on the camshaft improperly too, and may have...

Read the camshaft installation procedure carefully in the manual. One missed or misunderstood word can lead you to screw it up.

Have fun,

 

[retro]

That's the only "T" that I could find. I've checked a few times. There is some dashes then an F and then the T with the line above it. It's in one of the pics that I posted

This is the photo that you posted showing the incorrect ignition advance timing marks you used:

That is NOT a "T" !!!!

Start over... read the manual and follow directions. You'll get it right eventually... Come back and let us know how it goes...

 

[Carolynskiii]

Retro it seems to be the same "T" as specified in instructions from the forum on a 99 and newer 400ex

http://www.hondaatvforums.net/forum...-end-400ex-fourtrax.html#/topics/21959?page=1

 

[Carolynskiii]

and here's the pic of it in the manual of this bike is a 99-2002 Honda 400ex
Are there two of these or something?

 

[retro]

@Carolynskiii,

You are right! I just downloaded the manual and that mark is the correct one. Thanks!

@SickNasty,

Next thing to troubleshoot is whether the decompressor is put together right, and that it is fully releasing when the motor starts. Note the order of the parts and verify the one-way clutch is good, etc:

 

[TorqueDaddy]

No need for decompressor as he has an aftermarket cam.. the spring and pin were removed.

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[retro]

Aye, forgot about that. Got a timing light? Check the ignition advance thru the plug in the cover, make sure the CDI is advancing right.

 

[Carolynskiii]

or setting TDC the old fashioned way by unscrewing the spark plug and sticking a long skinny screw driver in the hole to make sure that piston is all the way at the top.

lol hopefully one us is bound to help these fellas hopefully sooner than later lmao

Something is not right at the cam or sprocket tho because those lobes don't look facing totally down.

 

[SlammedRanger]

I think the timing looks good...is this how it should look?

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The cam in that picture is 100% not in the right position if you are at TDC. The oil holes should not be pointed almost straight up like that. I bet the cam sprocket hub that goes onto splines on the cam is indexed wrong. There is 1 extra thick spline to try to make it harder to index wrong but it still can be done. But that would explain a lack of power for sure!

 

[SickNasty]

Literally just checked this after putting my head cover back on...?
So how would I set the cam then? How should it look? Can the sprocket go on the cam wrong? I'm at TDC, and the marks on the sprocket were there, I cant see how it could go any other way

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[SlammedRanger]

The cam is splined. And the hub that the sproket bolts to is splined also. Im not sure about hot cams. But my magnum cam i had to use my press and take the factory hub and sprocket off my factory cam and press it on my magnum. If that is what hot cams does also then it would be possible to put it on the splines wrong.

 

[SickNasty]

Here is a better picture with lobes down, and all 3 marks on the sprocket showing

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