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todds924

08 yz450 clutch.

11 posts in this topic

Just wondering if anybody knows if the 08's are using steel or aluminum DRIVEN plates. I know the part number for the Friction plates is the same from 06-08, but the part number for the driven plates has changed. The 08's are also using one less plate than the 06. I was thinking that if they were aluminum, this may be the reason for the adjustment problems I've been having. Thanks!

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I would be willing to bet that they are aluminum, as most all stock plates are aluminum.

The adjustment problem is due to clutch heat build up making the plates expand slightly which makes you have to pull the clutch farther for initial ingagement since the hub is at that point a little bit pushed out from where it would be if it was cold. Usually clutches get smoked not too long after the clutch lever begins to get "mushy" with extra free play all of a sudden.

I would check your oil filter after this happens to make sure that the clutch didnt begin to smoke filling your oil filter with clutch goo which can plug the filter starving the engine of oil and then...well, I'll let you guess what happen$$$$ next.

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The clutch I have in my 06 has steel plates. I have no problems with the 06 clutch....never have. Thats with 120 hours on it. If the 08's are aluminum...I will be changing them to steel. Kinda hard to adjust your clutch in the middle of a race.

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I knew the 06 plates were steel, but I am just going off of what I have heard about the 08 plates since I havnt had my 08 apart to look at the clutch yet.

They have pros and cons to each other. The aluminum plates heat up faster making them easier to overheat, but they also cool faster which makes the oil flow through the clutch more critical to keep the clutch cool enough to keep from burning up the friction plates. Aluminum plates also contaminate the engine oil much quicker and they reduce how easy they warp compared to steel since they dont have the same kind of material memory that steel does after it has been really hot. And they have a much lighter recipricating weight reducing the flywheel effect.

The steel take longer to get hot, but likewise also take longer to cool which reduces the chance of burning up a clutch unless you get them very hot which at that point they are much more likely to burn the clutch since they have a harder time cooling off quickly. They are also very dependant on clutch oil flow but not to the extent of the aluminum plates. They have a heavier flywheel effect as well. They tend to warp quicker when they get really hot repeadedly and they dont contaminate the oil like alumin plates do.

Just my $.02:blah:

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So have you raced the 08 yet?? Have you had any problems with the adjustment going away after about 15 hard minutes of riding? I'm not a big fan of aluminum clutch plates.. they wear to quick and wear out like an aluminum rear sprocket does. From what I see on the microfiche , The friction lates are the same from 06-08, only 1 less plate in the 08. I'm gonna check it out tomorrow and see if in fact the 08's are aluminum. If they are im gonna switch them to the steel 06's and race this week and see if my problem goes away. I'll let ya know how it works out.

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I dont race my bike. I use it for desert/dune riding and some mountain trail riding so I am not very hard on the clutch very often.

And NO I havnt had any problems so far but I have only put about 10 hours on the bike.

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Just checked out the 08 clutch today. They are STEEL driven plates. I hope it works well for the race this weekend.

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They are steel, the frictions are the same but the steels are much thicker in the 07 and 08. That is why the clutch pak in the 07 and 08 uses 7 and 8 instead of 8 and 9.

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raced the 08 today and am kinda disappointed in the clutch. At the start of the race with the freeplay adjusted proper, by the end of the moto the lever was half way in to the bar. This really annoys me because the clutch on my 06 has been beat for 100 hours and only adjusted once.

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They are steel, the frictions are the same but the steels are much thicker in the 07 and 08. That is why the clutch pak in the 07 and 08 uses 7 and 8 instead of 8 and 9.

do you know if the 06 clutch basket will work on the 08? I have a spare Hinson set up for an 06

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