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Yamaha´s engine hole

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Hi, I´m new here. This is my first post in thumpertalk. I´m from Chile-SA and I have a little question..

Which is the function of the hole that has the right side of the engine?

My brother is owner of a 2002 WR250F and when he tried to start it (with the engine warm) from this hole come out a litle bit of engine oil and burns in the exhaust expelling smoke and bad smell.

Thank´s for all

Best Rgds.

Ignacio

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The hole drains water and stuff out of there so when you take out your plug it doesn't all go in the engine.

Tighten up your spark plug maybe that's why it's leaking.

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Thank´s josh.

I check the spark plug (NGK CR8E) and it´s OK (I took it out and put it again).

Then I start the engine and from this hole blows air all the time...Is this normal?? or is I don´t know "a gasket problem"

ID.

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Is it blowing out the front of the engine right above the header?

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"Is it blowing out the front of the engine right above the header?"

Is blowing only from the little hole in the right side of the engine. The header is the muffler? (Excuse me but I don´t know so much english)

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air is getting by the spark plug somehow

which means you might be losing some compression because its not a tight seal

get a brand new spark plug and tighten it to the proper torque spec and see if that works

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Leaking head gasket? Or there could be an exhaust leak that you feel in the same area that appears to be coming out the hole.

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The head cover gasket is not leaking, and the exhaust is ok too. I´m sure that the air blows from the little hole. Besides sometimes appear engine oil from the hole and burns in the exhaust.

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that hole is there so that when you wash the bike the water that may get past your spark plug cap has a place to drain and not build up down in that hole.

If you've got oil and pressure coming out that hole, you've got some cylinder leakage around your spark plug or maybe the gasket around the spark plug hole in the valve cover.

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There are two possibilities here.

If the hole is the small, 5mm or so hole in the right side of the cylinder head that is in plain sight when looking at the side of the bike, that is the drain hole for the spark plug, and very little, if anything, should ever come out of it.

If the hole is an 18mm hole facing forward near the place where the exhaust pipe fits to the head, that is supposed to be plugged. The plug that was put there by the factory doesn't stay in place very well, and should be replaced with an upgraded one, if that is your problem.

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Had a similar problem on my 04 YZF. Oil was leaking out of the spark plug drain hole, but I did not have any problem with the exhaust. The valve cover bolts were loose,( I think they are called the valve cover bolts),the bolts on the very top of the engine. Tightened them up and it has been fine.

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Thank´s for all the answers guys. I learned a lot here.

grayracer513 : The hole i was talking about is the first hole you explain.

Fixins: I´m gona do what you said. I hope to solve the problem otherwise "oldnbold" was correct and is a cilinder leakage problem. In that case a mechanic should see the bike.

regards

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Thank´s for all the answers guys. I learn a lot here.

grayracer513 : The hole i was talking about is the first hole you explain.

Fixins: I´m gona do what you said. I hope to solve the problem otherwise "oldnbold" was correct and is a cilinder leakage problem. In that case a mechanic should see the bike.

regards

No need to take it to a mechanic, 2 things it could be and it is not major. Your sparkplug could be loose,causing the washer to let a little seepage by,shouldn't be oil though.

Or your valve cover gasket not sealing around the plug area. If you look at the valve cover gasket,you will see a round area of the gasket that seals on top of the spark plug area.If the gasket is not sealing around that area,oil from the cam compartment will get by the gasket.Oil will work its way down into the plug mount, and drain out that seepage hole.Save your money and tighten your plug, and check that area of the gasket.Button down the valve cover bolts evenly. :thumbsup:

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No need to take it to a mechanic, 2 things it could be and it is not major. Your sparkplug could be loose,causing the washer to let a little seepage by,shouldn't be oil though.

Or your valve cover gasket not sealing around the plug area. If you look at the valve cover gasket,you will see a round area of the gasket that seals on top of the spark plug area.If the gasket is not sealing around that area,oil from the cam compartment will get by the gasket.Oil will work its way down into the plug mount, and drain out that seepage hole.Save your money and tighten your plug, and check that area of the gasket.Button down the valve cover bolts evenly. :thumbsup:

Here are some pics of what bigred455 is talking about...

You'll need a 5mm Allen wrench to remove the 2 bolts holding down the valve cover, see the following pictures:

attachment.php?attachmentid=862&stc=1TN_IMGP5345.JPG

Check the valver cover gasket to make sure it's OK, especially the round seal that goes around the spark plug hole next to the vent hole - see the following picture:

attachment.php?attachmentid=863&stc=1

Here is a bigger picture of the valve cover and its gasket:

http://av-motorcycles.gotdns.com:9296/06YZ250F/checking_valve_clearances/IMGP5347.JPG

If the gasket is not OK, then replace the gasket and tighten down the valve cover better.

If you have the valve cover off, you may as well check you valve clearances too - see the following link:

http://www.thumpertalk.com/forum/showthread.php?t=394312

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Tell you what AV,You are OK :thumbsup: This isn't the first time I seen you help other posters with pics, to explain it to them if they quite do not understand. Also you are right on the money with the pics to my last post. :ride:

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Tell you what AV,You are OK :thumbsup: This isn't the first time I seen you help other posters with pics, to explain it to them if they quite do not understand. Also you are right on the money with the pics to my last post. :applause:

Thanks. :ride:

That's why I take pics - to help others and as references for myself. Pics do the SHOWING part to go along with the words of a post... :applause:

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Thank´s bigred for the information. I think that the problem is the gasket because I already check the spark plug and it isn´t loose.

av: thanks a lot for the pictures and tips, as you said pics do the "showing" part.

This weekend I´m gonna dismantle to see the gasket an the valve clerance

Regards

Ignacio

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Problem solved!!

Today I check the valve cover gasket and it was not in the right place in the spark plug area....that´s why oil was leaking and blow air from the drain hole.

I olso check the valve clerances and they was perfect, in the middle between the max and min specification.

All this problem begins when my brother take it to a "supposedly good" mechanic to check the valve clerance!!! He paid for damage in his bike!!!!

Here in Chile there isn´t good and honest mechanics.

Thank´s again guys

Ignacio

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It sounds like the gasket for the valve cover is torn on the inside where it seals up. If oil is coming out of that hole, THE ONLY WAY for oil to come out of that hole is for it to leak past the valve cover gasket. You need to pull the valve cover off and make sure that it is not torn or cracked. Cheers

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