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J-Marsh

09 yz450f clutch problem

6 posts in this topic

The situation:

I've got a 09 yz450 and i was burning up clutches left and right w/ only a single ride on them. Come to find out i was using full synthetic oil and that is a no no. After 4 or 5 clutch kits and totally replacing the entire clutch (basket, inner hub, press plate, ect) i now use 10w 40 non synthetic oil and things seemed ok. Now after around 10hrs riding time my clutch is slipping so bad i can't even ride it...i twist the throttle and it revs high but doesnt go anywhere. I've tried adjusting the clutch cable and it would help but now its to the point where that does nothing. cable adjusted perfectly. I dont understand *** im doing wrong here.

Some info:

-I'm just a wknd warrior...i never race.

-I change my oil after evey wknd.

-I dont ride the clutch more than normal.

-For some reason my clutch cover slowly leaks oil...w/ a brand new gasket. (ordered an aftermarket cover w/ new gasket that arrives today)

-oil i now use is Maxima 10w40 (non synthetic)

Please help....im ready to burn the bike and buy a honda :foul:

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You can drop it off at my house and I promise I'll burn it for you. :smirk:

Come to find out i was using full synthetic oil and that is a no no
What that is is BS. I've run full synthetic oils exclusively in all of the YZF's I own or have owned and not one problem with any of them.

Why anyone would ride the clutch at all on a 450 except in low gear at low speeds is beyond me, but here's what typically happens with the '07 and later clutch:

You start riding, fanning, and slipping it, and it heats up, so the clutch pack expands, increasing the free play. You respond by decreasing the free play at the adjuster, but when the clutch cools off, and the extra play disappears, you forget to readjust it to restore the play, and the clutch slips. Eventually this ruins the plates, and you replace them with low cost aftermarket plates that are even more subject to expansion that the OEM plates, making the whole effect worse than it was.

There are two cures for this:

  1. Lay off the clutch lever and use the gear box instead.
  2. Rebuild the clutch to '06 specs: http://www.thumpertalk.com/forum/showthread.php?p=7261940#post7261940

Use only OEM plates or premium quality replacements (no Moose, Tusk , or EBC , etc.)

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You can drop it off at my house and I promise I'll burn it for you. :smirk:

What that is is BS. I've run full synthetic oils exclusively in all of the YZF's I own or have owned and not one problem with any of them.

Why anyone would ride the clutch at all on a 450 except in low gear at low speeds is beyond me, but here's what typically happens with the '07 and later clutch:

You start riding, fanning, and slipping it, and it heats up, so the clutch pack expands, increasing the free play. You respond by decreasing the free play at the adjuster, but when the clutch cools off, and the extra play disappears, you forget to readjust it to restore the play, and the clutch slips. Eventually this ruins the plates, and you replace them with low cost aftermarket plates that are even more subject to expansion that the OEM plates, making the whole effect worse than it was.

There are two cures for this:

  1. Lay off the clutch lever and use the gear box instead.
  2. Rebuild the clutch to '06 specs: http://www.thumpertalk.com/forum/showthread.php?p=7261940#post7261940

Use only OEM plates or premium quality replacements (no Moose, Tusk , or EBC , etc.)

I am closer than he is... I will burn it for you...promise.. and do what gray said... he has never steered me wrong.. yet..

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From the dramatic response you gave me about the 'riding the clutch comment' i feel i need to clarify. What i meant by that is when accelarating out of a turn i MAY twist the throttle 1 or 2 sec before my other hand has time to completely let go of the clutch lever (that hand gets ansy).

I was told that synthetic was to slippery for the clutch by our local race shop JM Racing in houston tx by Jon himself. whether is BS or not i dont know nor care...i just want the bike to go when i twist the throttle.

I'd be glad to let you burn it for me for a small fee of $3500

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After reading your post Gray...i think what i may have done this time is rode the bike while the clutch cable was out of adjustment and caused it to ruin the plates. I'll make sure i stay on top of that. Thanks for your advice

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You're welcome.

But your advisor is still incorrect as to synthetic oil. Synthetic oil is NOT "slipperier". It's one of the enduring myths surrounding synthetic oils. It is true that there are some oils, most of them coincidentally synthetic, which are usually labeled "Energy Conserving" and carry the API stamp "EC II" on the back label that are probably best avoided, since they are loaded up with friction modifiers than might cause problems. It is highly unlikely that you would ever use one of these, since almost none of them are offered in viscosities higher than 30 weight. One exception is Honda 's HP4 engine oil, labeled JASO MB . But, it states right on the label that it should not be used with wet clutches.

Any oil labeled JASO MA (or MA2) is thereby certified as being OK for all wet clutch systems, and nearly all motorcycle specific synthetics and blends carry that compliance tag. For the most part, any automotive or commercial oil in 40 wt or higher is generally trustworthy in that regard, too. Although these are usually unsuitable for other reasons, they seldom cause clutch problems.

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