Timing help for '00 ex

[biggie400ex]

I am trying to get the bike back in time. I read the thread in the how too, but I have some questions. There is three marks on the fly wheel. Two lines pretty close together and another about an inch away that looks like it has an F beside it. What line do I put it on to get TDC? I have it set on the second line of the ones that are close together. Now the cam gear......do I look on the outside of the gear or the inside. I have been told two different things. The inside has two lines....should they be flush with the head? Or the outside has three lines.....two that should be flush and one pointing up. I have taken this route (the outside). If this is right, I pose a question. Once I get it all flush I turn the engine over one time till I get to the marks on the flywheel again.....but the cam gear is upside down????!? How do I know where to set it? I am pretty confused.

Eric

[biggie400ex]

Nobody can help me?

[GPracer2500]

The "T" mark indicates TDC. Align the mark on the side cover with the mark that is right next to the "T". Ignore the "F" mark and those other 2 hash marks that are further away from the T and F.

Only rotate the engine couterclockwise if the cam is stock (because of the auto decompress on the stock cam).

You should be looking at the outside of the cam sprocket.

The cam spins at half the speed of the crank. So you have to spin the crank twice to get one revolution out of the cam. Rememeber, there are 2 different TDCs--one on the compression stroke and one on the exhaust stroke. With the piston at TDC and the cam lobes facing up you are at the exhaust stroke TDC. Wtih the cam lobes facing down you are at the compression stroke TDC.

Sounds like a service manual would serve you well...

[sixer3]

if you are a replacing the cam or had it out of the head, and took it out without the crank being at tdc on the compression stroke, you need to make sure that when you see the T you ARE on the compression stroke, now and only now you may set your cam sprocket so that the 2 side lines are parralel with the head, and the top one is perpendicular, and that the cam lobes are for the most part facing down.....if you set the cam timing this way while the crank is at Btdc on the exhaust stroke Still seeing the T in the window your cam timing is messed up

the timing mark looks like this on the flywheel I I-

a T with a line over the top of it

[GPracer2500]

Originally posted by sixer3
if you are a replacing the cam or had it out of the head, and took it out without the crank being at tdc on the compression stroke, you need to make sure that when you see the T you ARE on the compression stroke, now and only now you may set your cam sprocket...

Without a cam installed there is only one TDC. The distinction bewteen the exhaust TDC and the compression TDC is determined by the cam--no cam, no distinction. You can install the cam with the lobes up or down--it's impossible to time a cam 180 degrees out of time. Install the cam with the lobes up and you've just located TDC on the exahaust stroke. Install the cam with the lobes facing down and you've just located TDC on the compression stroke. The piston didn't move, it was the cam that decided whether the piston was on the compression or exhaust stroke.

The only reason it is preferable to install a cam with the lobes facing down is simply to avoid the extra step of turning the crank 360deg before you install the valve cover and set the valve clearences.

[sixer3]

i think i was mixing myself up........you're right

[biggie400ex]

No....I had to replace my cam chain tensioner. And it jump out of time. Thanks for the info....I am pretty sure it is in time. Still can't get it started....I don't think it has any spark.

Eric

[DieselBoy]

well if there's no spark i pitty you. electrical sucks a big one.

[biggie400ex]

Great...thanks for the heads up. What started is all was I was riding with my son (he's 2), so I wasn't riding hard at all. The bike has always had a tick to it, even after the valves being adjusted and all. Well that ticking noise all of the sudden became very loud. I put it in the garage and shut it off. Checked the vavles and they were all fine. Went to start the bike and it wouldn't even start back up. So I took the head cover off and the cam chain was very loose, so I put a new tensioner in it. That fixed the chain being loose. I am pretty sure I have it back in time and it still won't start. It turn over just fine just won't fire up. PUt a new plug and nothing. Correct me if I am wrong....If I put the pug in the wire and try to start I should see a park out of the plug , correct? Well, I have seen it spark once. I have tried many times with different spark plugs. So I guess I will try a new wire and go from there. Unless someone has any other ideas?

Eric

[DieselBoy]

test the spark. how? remove the plug from the motor, or, use a spare. touch the threaded section of the plug to the side of the motor, and wedge it there firmly (NOT with your hand, use a stick) turn the starter over, making sure the Killswitch is disabled. You should see a nice crisp blue consistant spark. if you do not, check ALL your connections and plugs. Otherwise...its time to test your coil/stator/etc.

Mine stopped sparking, and it's the stator! I'm getting my stator friday!

[400exrules]

when at tdc their should be alittle bit of play in all 4 rocker arms....if their is only play in 2 of them, rotate around one more time to the T, and it should be TDC

[biggie400ex]

ok...I have spark. If its not the timing what else would make it not start like that? What could have gotten damaged when it jumped out of time and would that make it not run?

Eric

[DieselBoy]

valve tap piston (bent)... umm...bent rocker....low compression...etc..

[biggie400ex]

I tried starting it today and it would turn over but not fire up.....every once in a while it would back fire? I guess I have to tak e it somewhere now b/c i have no clue.

Eric

[GPracer2500]

It's still not timed right.

[DieselBoy]

you either: 1 do not have the timing right 2. your engine is not generating sufficient compression 3. your spark is not consistant/sufficient 4. your not getting fuel

[biggie400ex]

ok....How do I test compression? and fuel? The spark is fine. One question on the timing. Do i set the timing when the chain is tight or lose?> B/c it changes when I tighten the tensioner. i have been setting when tight. Thanks for all your help.

Eric

[GPracer2500]

Originally posted by biggie400ex
o...Do i set the timing when the chain is tight or lose?> B/c it changes when I tighten the tensioner. i have been setting when tight. Thanks for all your help.

Eric

The cam sprocket is indexed first and then the cam chain tensioner is installed. Then you re-confirm that the timing is still correct. There should only be a tiny (if any) difference with the tensioner in or out.

Seriously dude--you need to get a shop manual and follow the instructions. It's all spelled out with pictures and everything. I'm not trying to be a jerk, but if your not sure how to check for fuel and compression than you probably shouldn't be trying to time your valvetrain.

Nonetheless, you can open the drain screw on the bottom of the floatbowl. If fuel comes out than it is very likely you are getting fuel. Compression is tested with compression tester. It's basically a air pressure guage that screws into the sparkplug hole. But the data from a compression test will be thrown off if the valvetrain timing is wrong.