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06 CRF250X Leaking Oil From Cylinder and Won't Start

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Hey I have a 250x that is leaking oil from the place shown in the picture. (Right side of the cylinder) Does anyone know what that hole is and why oil would be leaking from it?

When I bought the bike it had been sitting for a few years. It was pretty difficult to start, several kicks or prolonged use of the electric start were needed. I replaced the spark plug which was very oily. This seemed to help the starting problem for a bit but it came back. Now it doesn't start at all.

Thanks!

IMG-20111016-00155.jpg

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Ur carb isn on right... Lol j/k change valve cover gasket and there's a gasket on top of tue spark plug hole when you take of the valve cover. Wile ur in there check your valves, install a new spark plug and make sure it's in tight. You need to squish the crush washer on the spark plug when tightening it. Here's how to check valves( http://www.thumpertalk.com/forum/showthread.php?t=179775 )

GOODLUCK!

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I'll be checking the valves today. I drained the oil yesterday and it was very very black. There wasn't much of it either, less than half a liter or so. Should I be changing my rings?

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Another thing I noticed was the engine is very hard to turn over by hand with the kickstarter. I have the engine out of the bike right now so I can't kick it. Spark plug is out.

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if the spark plug is out and you can't turn it over by hand, further investigation is required.

When was the oil changed last?

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I bought the bike this spring and the previous owner didn't know when the oil was changed last. I didn't change it (I know I should have) I just topped it up because some oil had leaked from the spark plug drain.

Here is the piston:

IMG-20111025-00185.jpg

IMG-20111025-00184.jpg

And the cylinder:

IMG-20111025-00187.jpg

Here are my valve clearances when I checked them.

Left Intake

Measured Clearence: 0.0508

Spec. 0.127

Right Intake

Measured Clearence:0.1016

Spec. 0.127

Left and Right Exhaust

Measured Clearence: 0.2286

Spec. 0.280

I will see if it turns over by hand with the cylinder off right now.

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I would suggest a new piston kit (barrel looks ok) and either a temporary fix of re-shimming the valves or bite the bullet NOW and get steel inlets fitted while its in bits (re-shimming will only last a few hours at most) sort out the valve cover seal (its awkward to get it onto the spark plug ext tube properly when replacing the valve cover)

In future change the engine oil regularly !!! (install a new filter every 2nd engine oil change)

Don't forget there are 2 lots of oil to change in these engines

1. engine oil

2. transmission oil (no friction modifiers due to wet clutch)

Good luck with the rebuild

Ian :thumbsup:

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I am just trying to educate myself, I thought when oil was getting past the rings and burning it created a halo on the outer edge of the piston due to oil burning hotter than the fuel mixture.

I see all the mess on the side of the piston but no halo.

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By the looks over your pictures to I saw some copper colored flakes(Crank) I would replace the crank bearings to.

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While there was nothing mentioned about oil consumption, its not at all unusual to have some carbon on the piston edge above the top ring especially with a high hour engine. In most cases carbon is just whats left from the fuel burning process.

Usually there are good indicators of the engine burning oil such as smoke from the exh and oil consumption. Again not saying this engine was or wasnt burning oil but the photos do show it was leaking oil.

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