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BigNick98

Help Before I turn to dealer?

20 posts in this topic

My 05 YZ450f leaks oil from the bottom of the bike. Not sure where it's coming from but it only leaks when it's hot. Also it overheats faster than it should during woods riding but is fine when your in an open field. Does anyone have any ideas or help to what I can expect the dealer to find?

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First find where the oil is coming from before taking it to the dealer and also have u checked ur antifreeze. Is it something that has always been or just started?

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The bike is new to me. Coolant is full and seems to be flowing fine. I can't tell where the oil is coming from. Is it possible to leak from the shifter?

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Mine was leaking on the black plastic above the shifter. Had to get a new one and new seal

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gear selector seals are common

also the seal behind front sprocket

they are cheap to replace.

run engine ice with a 1.4 radiator cap

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please take some pictures of the oil leak so we can help you out. On these 4 stroke YZ's there are too many oil leak sources to help you identify without pictures. I would try a higher psi radiator cap, a 1.4 or 1.6. Make sure you don't have junk trapped between the radiator guards and the radiator.

We will get this figured out so you don't have to go to the dealer, but we need some pics.

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Oil can, of course, leak from just about anywhere. Seals are your first suspect. Shifter, counter shaft, water pump.... I've seen a couple of right side crankcase cover gaskets leak from below the kick starter, stuff like that.

Pull off the skid or glide plate, clean everything as well as possible, and let it dry. Then dust it with baby powder or foot powder (any kind of talc) and ride it. The leak should leave a trail in the powder.

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Thanks a bunch for all the interest guys, I'll get some pictures up soon. I'll just take them from everywhere I can think of. I can't tell where it's leaking from, I just know it's leaking because it drips on the ground when it's hot. Also thanks for the tips on the radiator, I'll clear the system and add engine ice and hopefully that helps. What exactly does a 1.4 psi cap mean?

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Ok guys here's some pictures. If there's anything else I need to take just let me know. This is of the shifter and somewhat underneath. Thanks for the help ImageUploadedByThumper Talk1368288745.531935.jpgImageUploadedByThumper Talk1368288763.713992.jpgImageUploadedByThumper Talk1368288785.696098.jpgImageUploadedByThumper Talk1368288801.545619.jpgImageUploadedByThumper Talk1368288857.829389.jpgImageUploadedByThumper Talk1368288883.530034.jpg

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Oil can, of course, leak from just about anywhere. Seals are your first suspect. Shifter, counter shaft, water pump.... I've seen a couple of right side crankcase cover gaskets leak from below the kick starter, stuff like that.

Pull off the skid or glide plate, clean everything as well as possible, and let it dry. Then dust it with baby powder or foot powder (any kind of talc) and ride it. The leak should leave a trail in the powder.

This. Times 68.

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Counter shaft, output shaft. Check the condition of the collar under the seal and replace the large, thin O-ring that seals that to the shaft.

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Thanks guys. I don't have a manual or anything so google will havta help me through the names and where they're located

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Manuals:

http://www.yamaha-motor.eu/eu/services/owner-manuals/index.aspx

http://www.yamahaownershandbook.com.au/?r=0

Engine Ice WITH Water Wetter works very well. Engine Ice alone will add about ten degrees to the boiling point compared with green ethylene glycol stuff, but it's really nothing more than distilled water and propylene glycol coolant pre-mixed. You could do the same thing yourself, but you'd end up with 1 3/4 gallons of stuff to store, so sometimes buying the ready to use product makes sense.

Increasing the boil point improves coolant retention when the engine runs hotter, as when riding slow, tight trails. Running a 1.4 bar cap raises the pressure on the cooling system, which again raises the boil point, helping to retain coolant. A balance has to be found in this strategy, because raising the boiling point lets the engine run hotter before the boilover happens, and the boilover is often the only thing that alerts the rider to the heat, so it may not always be the best solution.

Water Wetter works as a surfactant, which is to say that it breaks down the film tension of water to increase the water's ability to transfer heat from and to the things it touches. Using a glycol based coolant of either kind will help with this, anyway, but Wetter can improve things just a little, even so.

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And when you replace the countershaft seal be sure you don't have the chain too tight. That is very often the reason for failure.

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And when you replace the countershaft seal be sure you don't have the chain too tight. That is very often the reason for failure.

Usually that is the case.. better to be a little loose esp if ur someone that uses ur full range in suspension.

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I figured out my problem with help from a buddy who's a dirt bike genius. All I did was switch the stock 42 jet to 50 and it runs better than ever. Just for help to others out there having the same problem. Also discovered the leaking oil was the seal behind the shifter not the counter shaft seal.

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