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Transmission Oil Leak 300 EXC

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I was out riding today on my 02 300 EXC and i figured I'd play with the power valve some more. I felt it needed a little more hit from the bottom, so I kept scewing in the adjustment. I got to point where I could feel no effect and I stop fooling with the screw, leaving it on the last setting.

When I hauled the bike to the local power wash in noticed oil in the bed of my truck. At first I glance I noticed a pooling of oil around the powervalve adjustment screw. I removed the skid plate once home and performed a detailed inspection. No signs of cracks or anything unusual sticking out out the casing. I unscrewed the powervalve adjustment out back to its original position. I refilled the transmission oil, it seemed to be about 1/3 qt. low. I have the bike sitting up right and as of now no leaks. I haven't cranked it up yet, ran out of time.

Is this someting that could happen when you turn the powervalve adustment screw too much inward?

Any idea what happened?

Edited by T30

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i have the same bike and had a small

leak from the adjustment screw.

there is an o-ring you can replace if it gets to bad.

wher in ga. are you. i'm in north ga.

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Thanks. I think I may have busted the O rings. I looked up the diagram on the KTM-World website and it shows two O rings inside the adjustment mech.

West Central Ga, Harris Co, near Columbus. I do spend quite a bit of time in Lumpkin Co (Dahlonega) when the weather is good. I have some friends that live up in the foot hills that like to ride.

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cool, the o-ring is easy to replace.

i'm outside dawsonville.

i ride durhamtown and moto mountain.

and the twisties in the mountains on the street bike.

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If you turn the screw all the way in it essentially is somewhat loose in the case. The threads on the screw are still in contact with the threads in the case but only due to the pv spring pressure on the backside. My guess is you screwed it in so far that it allowed oil to pass around the adjustment screw. Doubt that you ruined the o ring, unless it still leaks next time you ride it. Should be fine.

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what weight oil do you guys use, my local dealer suggested that use klotz flex drive30 in the gear case, ever use it, i use klotz mix oil and always liked it, oh yeah this is my first two stroke in about 9 years so i was just wondering

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i run 80w/90w gear oil

and syn. two stroke oil 40-1.

That's what I run also.

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my dealer gave me klotz flex drive30 which is 75W/80 and my pre-mix ratio is 60-1. i havent had a two-stroke in about 9 years and couldnt remember anything but the klotz pre-mix and the smell that it made, loved the smell.

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Yes gotta love the smell. I've been riding 4Ts since I got back into riding a few years ago. Since 2009 I've gone through 2 KTM 300s. These pingers bring back lots of memories.

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i still have my 4t but i got me a husaberg TE300 about two months ago and i love everyhing about this bike, everytime i hear it or smell it it takes me back to when i was a kid

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