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Justin89

Updated:2006 yz450f: Found pieces of metal behind ignition cover...(Found Problems)

31 posts in this topic

Okay guys, I posted a thread early about my chances of my crank and valves being good. I got a call from the guy that is doing my build and he said that he found pieces of metal behind the ignition cover on a "magnet"? He said wont know exactly where they are comming from until he takes the bottom end apart tommorrow. He did say that he checked the crank and that it wa good, my valves were good, and my cylinder and piston were good. So is this good news or bad news then? I really dont know a whole lot about this stuff so please someone help. Where do you think that these pieces of bearing are comming from exc. Any help or suggestions would be greatly apreciated...let me know if you need any further information...thanks!

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Being an 06 it might be that little roller piece of junk thing that falls apart and makes them hard to shift. If the crank, valves, piston, etc. are all good it had to come from there or the clutch somewhere I would think.

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Well I just replaced my clutch about five rides ago so I dont think that that would be the problem...he said he's gonna check the other bearing in there as well...what other bearings could it be?

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The magnets in the flywheel are very strong, and they can and do capture stray bits of steel debris. If you can't find anything in particular wrong, don't worry too much about it. It could be no more than a chip off a trans gear.

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Okay thats good to here...I'll let you guys know for sure what and where it is comming from tommorrow night...thanks!

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The stuff is probably more like a fine dust - it's what wears off the gears where they mesh.

If it isn't big pieces (like crumbs) or a huge amount, just remove them with a rag and plenty of cleaner.

Also check the backside of the flywheel - you'll likely have some in there as well that you can wipe up.

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The stuff is probably more like a fine dust - i
The flywheel routinely collects that kind of stuff. It's typical to find a "dried" layer of iron dust packed onto the inner diameter of the flywheel. It usually has to be scraped out. The unintended secondary function of the part seems to be that of a magno-centrifugal oil filter.

Big chunks are a little more unusual.

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The flywheel routinely collects that kind of stuff. It's typical to find a "dried" layer of iron dust packed onto the inner diameter of the flywheel. It usually has to be scraped out. The unintended secondary function of the part seems to be that of a magno-centrifugal oil filter.

Big chunks are a little more unusual.

Well I think it's a litte bit larger than dust because he said he could cleraly tell that they were pieces of a bearing but dosent know which one...

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Are these pieces squarish flakes of metal, pieces of bearing cage, or actual balls, say, 2mm in diameter?

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Are these pieces squarish flakes of metal, pieces of bearing cage, or actual balls, say, 2mm in diameter?

I think there pieces of the bearing cage not the balls. Before i took my bike in to him for the rebuild, I had no problems at all with the bike...it ran, started, everything fine so idk if this is just premature wear or if I am just lucky to catch this before something catistrophic happens inside. Or if this is just normal wear and tear? I have a religious maintaince schedule and am a fan of the 450 low end torque so I hardly ever hit or come close to rev-limiter (if that has anything to do with anything). Im actually a gear high ususally...:thumbsup:

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I had a bearing cage give and in turn take out the whole bearing (inner chase was totalled too) - the one on the output shaft.

Prior owner had chain too tight, first thing I noticed when I pulled it off the truck, loosened to specs, rode for a month - got tiny leak at countershaft - winter came - replaced seal, oring and collar - checked bearing - looked good, maybe 1/1000 play on output shaft - obviously already too much play since once spring came, I put all of 3 hours on the bike and detonated the bearing without ANY further signs - the new seal likely hid the fact it was becoming a bigger problem.

If you get it now, you'll save yourself replacing all bearings, but if there is the slightest doubt about a bearing, replace it or you'll be in there again soon.

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I had a bearing cage give and in turn take out the whole bearing (inner chase was totalled too) - the one on the output shaft.

Prior owner had chain too tight, first thing I noticed when I pulled it off the truck, loosened to specs, rode for a month - got tiny leak at countershaft - winter came - replaced seal, oring and collar - checked bearing - looked good, maybe 1/1000 play on output shaft - obviously already too much play since once spring came, I put all of 3 hours on the bike and detonated the bearing without ANY further signs - the new seal likely hid the fact it was becoming a bigger problem.

If you get it now, you'll save yourself replacing all bearings, but if there is the slightest doubt about a bearing, replace it or you'll be in there again soon.

Thats what I told the guy...we were both worried about something detonating while at race or jumping or something like that. Im gonna have him check them all...the only bad thing is that they aint cheap ordering from Yamaha :foul:

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Well got some bad news today. I found out today that the piece/arm that "holds" your bike into gear went out...the bearing within was almost completely gone. This is what was causing my bike to drop into neutral from 4th/5th gear! This in turn, caused some of the teeth on the gears to break. My oil pump also sustained some fairly major damage and will probably be needed to be replaced. I will also be replacing a couple other bearings along with the cam chain and tensioner. I'm prolly looking at over $1000 in engine work alone:crazy: (including parts/labor and top end rebuild)

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Well got some bad news today. I found out today that the piece/arm that "holds" your bike into gear went out...the bearing within was almost completely gone. This is what was causing my bike to drop into neutral from 4th/5th gear! This in turn, caused some of the teeth on the gears to break. My oil pump also sustained some fairly major damage and will probably be needed to be replaced. I will also be replacing a couple other bearings along with the cam chain and tensioner. I'm prolly looking at over $1000 in engine work alone:crazy: (including parts/labor and top end rebuild)

yikes Justin how long was this symptom going on? 4/5th into neutral....one ride several rides?

Was this the shift fork or what? I am confused...arm and bearing?

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The indexing lever for the shift cam.

That would be that little roller POS thing I referred to early on in this post... couldn't remember the technical name :thumbsup:

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The indexing lever for the shift cam.

Grey I hate to ask you this - but can you plz put a parts fiche pic up on this particular part? If you have one that is.

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