Hi !
I have this problem with my 87 XT, after it sits for some time the oil is ending up in the bottom of the engine.
The question is, is there a valve that can be failing and drop all the oil down ?

KEDO - Performance Products search itemno 27815

Thanks Jens.
Next question : Where is the possision of the valve ?

In the clutch sidecover as I recall

All this info is for my '03 xt600, But I would think the same goes for yours

Hi,

This oil valve is in the crank case gasket face which is exposed when the right side cover (clutch side) is removed.

Years ago I think that I read on this site that this valve only prevents oil from draining out of the head when the engine stops, but the Kedo info says it prevents oil draining from the oil tank and into the engine. I wonder which is correct.

If you do replace this oil valve, you may need to remove the exhaust header to allow you to remove the banjo bolt that connects an oil pipe between the top of the crank case and the clutch cover. But this pipe was added some way through XT600 production, so not sure whether your engine wil have it.

I would be very interested to hear if changing this valve does reduceor stop oil draining out of the oil tank, as I also am having this problem with my 1993 XT600z 3AJ tenere

Mark

"I would be very interested to hear if changing this valve does reduce or stop oil draining out of the oil tank, as I also am having this problem with my 1993 XT600z 3AJ tenere"

Hi Mark,
1st experience was an engine that lost oil into engine overnight, rebuilt with new valve and oil pump, solved the problem. 2 years and 20000km later it still holds oil for days, does not leak. But inconclusive as both parts were renewed.

Now busy with 34l engine but never ran it before rebuild so no history but:
I have done a test with a stripped 34L engine where i assembled empty cases and the old well worn pump and check valve without clutch cover. Used ATF in the oil tank rigged high above. The experiment failed because there were no leaks!

Oil from the tank can 'leak' into the crankcase only via the oil pump and the check valve you mention, or via missing seal rings between engine cases. All oil from the pump must pass the valve, lifting the ball off its seat against the spring. Thus it is a non-return valve but also a forward check valve until pressure overcomes the spring.

I would always use a new valve seat, Yam part 583 13113 00, cheaper than most oil seals in the engine. Never use anything but the correct spring. The ball can be obtained from bearing suppliers, 3/8" diameter.

Interesting that the oil pipe to gearbox fitted to later engines may to start at silver case engines in 3AJs but not in silver case 2KFs.

Regards,
p

Hi Pete,

Thanks for your detailed reply.

As I need to replace the clutch side engine case gasket because of an oil leak from here (as well as the one from the cylinder head core plug!), so I will take the opportunity to replace the three parts of the oil check valve while I am there.

I will try to remember to post back whether this stops the oil level dropping about 20mm in the first few seconds after I turn the engine off.

Mark

Thanks all that have written here, here is a lot of the information I needed.
Will order the parts and replay here when job is done.
Thanks again.

Finally got time to do this job,did take of the cover today and cleaned it and discover that there is a lot of corrosion on the inside of the cover. I think I will replace it later, any one know where I can get one ?
I did notice that the old spring was a lot shorter than the new one so i hope this solve the problem, there was no damage to the seat for the ball.
I will take picture tomorrow and put here.

You can buy the cover used on ebay or new in the Yamaha dealer.

Mezo : The clutch cover is the one I need.

xtroc : I suppose that the dealer will have problem deliver this, the reason is that it`s a 87 mod 1vj and after my understanding that parts for this mod is hard to get. Question is if there is cover from never/older mod that fits, this mod have electric and kick starter and I`m not sure if I can use cover from other model but if there is please tell me witch one i can use.

I have changed the spring, ball and seat today and put it back together, and a new problem showed up. Now it seems that the decompression system not work in the engine, no movement when i try to start, turn the engine. It seems that there must be something wrong inside the bottom part of engine because the lever on the head and the lever in the cover have movement when done manually.
Any idea what can be wrong/ broken ?

I have seen one on e-buy but it looks very bad on the surface, I might just buy it anyway.

My cover have a lot of pittings inside so i think it`s no help to clean it.

The wire for decompression system is working, when I move it manually on the cover the lever and wire is moving.

Here is some picture, please have a look and tell me if you see something wrong. My upinion is that there must be something wrong with the connection between the lever in the cover and the shaft on the kick, but I have no idea what is wrong/missing.

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Damn the cover looks nasty inside

It don`t look good that is for sure, hopefully I can get one soon.
Does anyone see any thing suspicious about the decompression system ?