should valves be oily?
 

Hi

I opened the valve cover on the xt600 and see oil on top of the valve and the adjustment screw is a bit oily too. Is this normal? I woul think that this thing should be dry?

I took a picture but cant post it yet..

Also the screw on the left side of the crankcase under the cover, the one you turn around anticlockwise to find tdc, it was a couple drops oil in there too..

:s
 

Im pretty sure i saw oil on the swing wheel while looking for the T mark :o And im pretty sure thats not supposed to have oil on it at all. Feel free to enlighten me *fingers crossed*

Thats the way it should be, full of oil :-)

Thank god :)

Heres the images (taken with mobile), click for bigger size.

http://img696.imageshack.us/img696/4...ontleft.th.jpg

http://img695.imageshack.us/img695/8...ntleft2.th.jpg

http://img219.imageshack.us/img219/1...ntleft3.th.jpg

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Things would wear out pretty quickly if there was no oil up top. If you think how quickly those valve rockers and the cam is moving when your reving the engine they need some lubrication. When you take the small covers off to get at the flywheel nut, to rotate the engine, and the one to check the timing marks then there should be a little bit of oil coming out of there too. In fact as you rotate the engine the oil pump will cause an extra bit of oil to come out. It sounds as if all is well. All of the Yamahas that I've had also have a little bleed screw somewhere on the top of the block to check that there is oil getting up to the top after an oil change, it should be shown in your manual.

Never worry about asking basic questions, we're here to help.:thumbup1:

Thanks :)

I have trouble understanding when its on the compression stroke tdc.
People say watch the rocker arms, is it when the valve/arm goes up or is on its lowest position yor supposed to measure? I would guess when its on the highest position just becase its hard to measure it on the lowest position haha.

I turn the engine and the valve goes down then suddenly it goes fast up, then when i turn the engine a bit more the valve slowly goes a bit more up until it starts to go down again.

Thats due to the profile of the cam acting on the cam follower (rocker arm). It needs to have a nice gentle slope to push against the valve spring to open the valve, closing it is easy as the spring helps, hence it's quick. When the valve is closed there should be a small gap between the cam follower (rocker arm) and the top of the valve. This is to allow for expansion as the engine gets hot. This is why you should check it when it's stone cold (maximum gap). Think yourself lucky you have this type of valve adjustment, bucket and shim is a whole other kettle of biscuits.

I'm sure if you Google "XT600 valve adjustment" you'll get a full write up with pictures.

Here's a write up for an XT225 which will be basicly the same...

DIY XT-225 valve adjust - XT225+250 Rider's Group

So that means, since the rocker arm moves quick "upward" thats when the valve is closing right?

And the valve is supposed to be measured when the valve is closed, so that means I have to measure it when the rocker arm/nuts and the valve has moved to that highest position+when it feels like compression stroke (? ) (Read, highest position = when you look through the whole into the valve and rocker arms while rotating the engine those will move down and up, down=further into the engine and up/highest=closest to the whole your looking through, just thinking loud here..)

Btw one thing that could help understanding it is, when its compression stroke tdc the valve will be closed or open?

I think i get it now, people say look for the T and tdc but make sure its on the compression stroke..

You could instead say: look for the T and tdc, then make sure that the valve is closed/rocker arm is highest up, this will mean its the compression stroke..Correct thinking?

If you find the T mark and check the rocker arms and they are on the furthest down position the valves are open..and its on exhaust stroke..

Go through this sequence.
Remove valve caps and the two caps on the L/H crank cover.
Take the spark plug out to ease rotation and control.
Rotate the engine anti-clockwise until the inlet valves have opened (gone down) and then closed again (come up). The inlet valves are the ones at the back of the engine next to the carb. Use a socket on the nut you will see in the larger of the two holes.
Look through the small hole on the crank cover and watch for the marks to appear as you continue to turn the engine. You will see an F first, followed by a T. Both letters will be laying on their sides and there is a notch in the casing to line them up with. You want the T. The F is for ignition timing.
Adjust the valves to the correct clearance then rotate the engine right through the sequence again and check them once more. Two turns of the crank gets you one turn of the camshaft.
Finally, look at the first thread on this list and download the manual. Then you'll have pictures to look at too.
Good luck and feel proud when you've achieved the result.

Geoff

First thing is to make sure you're turning the engine in the right direction, not backwards, my XT250 is anti-clock. Check online for your bike. Then remove the spark plug and look inside to see when the piston gets to the top. If both valves are closed then its on the compression stroke. Use the timing marks on the flywheel to locate TDC but it's easy with a 2 valve single to see with your eye. Not so easy when you've got 16 of them dancing around up there!

I couldnt see the mark clearly though I found a very long line that appeared after the valve was closed, I then checked and a 0.006" was very tight fit.. 0.006" is 0.15 something millimeter,my manual says 0.1 to 0.15mm on exhaust so..if i was at the correct position its maybe a tad bit open but i didnt do anything to it.. It got dark and late so I didnt check the intake valves yet.

It sounds as if the spec is the same as my 250.

Exhaust 5 thou = 0.13mm (spec 0.10mm-0.15mm)

Inlet 3 thou = 0.08mm (spec 0.05mm-0.10mm).

You expect the gap to get bigger with wear so it would make sense to set it near to the minimum in the range to allow for wear before the next check. Try a smaller guage, I usually go in the middle and see how it feels.

Yes thats the same, the owners manuals says exhaust 0.1-0.15, intake 0.05-0.1, unfortunately i suddenly saw i bought feeler gauges on inches instead of millimeters so i just tested with a 0.006 inch and it fitted but very hard = 0.1524millimeter

Its very hard to find the T mark, if its on the side maybe its like this?
--------| ? and not like this: T

TDC is only critical for ignition timing as the spark has to be a few degrees before TDC to ignite at the correct time. The gap between the valve and rocker arm is constant over quite a few degrees so as long as there is a gap and you can see the line in the small window then that should be OK. The old trick was to put a dowel or metal rod in the sparkplug hole and watch it reach the maximum. If you do this make sure that no debris is left in the bore or the dowel etc doesn't get crushed. Using gauges in inches is fine just find a converter online to find the correct setting. As you say a 6 thou feeler is too tight but so it should be as that's outside the spec. You need to use a smaller gauge, or combination of the smaller ones to make 4 thou which is 0.10mm or 5 thou which is 0.13mm.

Here is a pic that might help youAttachment 3261
You have to move very slow when closing in on the last mark, the "T", or you will roll past it

You should also be ablo to just spin the wheel and watch the valves, when the intake valves are openening, the exhasut is closed, and you can adjust them (exhaust) and the other way around.

Not quite! It's often the case that the inlet valve starts to open just as the exhaust valve closes, known as valve overlap. Just stick to the book method - after all, it works!

Geoff

No offence, but as this thread shows, it can be wery hard to get all the things lined correctly up the first couple of times, using the method in the manual.

This works too, and gives a much wider "area" where you can adjust. You can see with the naked eye when valves are not into play, so I really cant see the problem. Have you personally seen valve overlap on the xt600, or are you "making" up a problem? Even if this was the case, and you are stupid enough to not see the valves move, you could do the adjustment, when the other valves are wide open. Or is that also a problem?

Come on, lets all be friends instead =)

I find it easier and quicker, it might not work for you, but it does for me. That doesn't mean its wrong does it?

Were all trying to help, and theres different approaches.

I'm sorry Jens. I wasn't being dismissive of your method, just giving out the warning, that's all. I'd need to see a valve timing chart to know if there's any valve overlap or not. But there could be. I will stick to my point though, which is that when you're learning something new it's best to learn the correct method. That way, no risks. I did also suggest to Bergspre that he go to the thread for downloading the manual. That could make his life easier all round.
Either way, you're right in that all advice has a value so please don't let me discourage you from passing it on. :thumbup1:

Kindest regards,

Geoff

Well I thank you all for trying to suggest, different approaches can often help understanding the concept behind it all.

I already have the manual + the clymer manual + the owners manual.

When i watch the valve I see that it moves upward and closes. When it reaches the top theres a part where I turn the engine and the valve seems to not move, is this a safe moment to set the gap?

As I understand the valve closes and stays there for a while(while turning engine) then it goes down again/opens up. So, if it stops at the closed position it should be safe to adjust it once you see that it stopped moving, is my theory based on all you guys's info..

I tried to make a little chart of how I see it at this moment..it may be wrong so feel free to comment.
http://img202.imageshack.us/img202/7...losophy.th.jpg

Once the valve has closed, as you describe, then the piston will be moving upwards towards top dead centre, trying to compress the fuel/air mixture. This means the timing mark visible through the small hole on the LH crankcase will soon be in sight. Keep turning the engine, either with the rear wheel or a socket on the nut on the end of the crankshaft (anti-clockwise), and when you can see either the F or the T, then all four valves can be adjusted at this point.
Hope that helps,

Geoff

Thanks for all the help guys :)

Finally spent the day yesterday and adjusted the valve.
It actually feels much "tighter" now, especially from 3500-5000rpm and a bit stronger, which is strange,the valves wasnt that much off except one of the exhaust valves that was 0.01 more then max. Its less noisy above 3000rpm then before.