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Discussion Starter #1
Picked up a 2012 grizzly 450 cheap and knew it had problems. I haven't ridden it much but it does smoke and use some oil. I checked the valve lash and the intake was super tight. I set both to the upper end of specs.

I then drained the oil to find metal chunks in the strainer. The biggest size was a sliver about half the size of my thumbnail. Obvious, this isn't good, but I am wondering if is possible to be wet clutch or gear related. These particles are magnetic, and I think that one is too big to be part of a ring.

Display only shows like 125 hours on the machine. Other than the smoke, it runs pretty good, so I cant imagine something in the top end making this much metal and still run decent. I'll have access to a bore scope tomorrow and im going to see if I can take a look in the cylinder and see if I can see anything from the strainer hole. Thanks in advance for any insight.
 

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Are you 100% sure it's magnetic?
I ask this question because it's very common to see aluminum chunks in the oil strainer. Clean the chunks in solvent or degreaser to give them a good inspection.
 

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Discussion Starter #3
Are you 100% sure it's magnetic?
I ask this question because it's very common to see aluminum chunks in the oil strainer. Clean the chunks in solvent or degreaser to give them a good inspection.
I put a round magnet and they all jumped off the paper towel and clung to the magnet. Most of them are now in the trash, as I determined confidently that they were magnetic.
 

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Discussion Starter #5
I guess my question is, is it possible for this to be coming from the clutch/transmission area? They are definitely not aluminum.
 

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I guess my question is, is it possible for this to be coming from the clutch/transmission area? They are definitely not aluminum.
It's a possibility....but extremely unlikely without other running issues. It would take the wet clutch to be metal on metal with the clutch drum to make metal flakes or filings. You would know if this was happening. The bike simply would not move and you may hear it grinding away.

It's possible to come from the transmission gears, but again, highly unlikely. The transmission gears are made of high carbon steel, which usually chip and crack rather than flake....and again as well, you'll feel and hear that when operating the machine.

I would suspect the metal came from the cylinder, wrist pin, cam lobes, rocker arms tappets, etc...
 
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shame you didn't do some pictures..

the way you described the lack of intake valve lash is interesting.....if a cam bearing failed you would have an awful noise...but pull the 2 valve covers and peek carefully around the cam with the borescope while you roll the engine around with a ratchet.. the oil pump on the little beast is robust..the cam and tappet contact surface should look bright and clean and shiny with No signs of blue overheating or grooving... I have seen the feed tube plug with coked oil, overheat the top end and flake pieces of the cam lobe....maybe.


does it start easily, gear select ok without clicks or pops...as dezz mentioned the gears will break tips off in chunks, but usually not as you have described..

walt
 

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Starts okay with choke. Doesn't idle too well without but it's also leaking gas from carb. I inititially attributed idle issues to to that. I get a carb kit in the mail today. Seemed to shift well. Has a little drag like engine braking when you let off the throttle but feels different than other models. That's why I was wondering if it could be the sprag in the clutch. Sorry I didn't take pictures. When I first found them, in my head I was taking the head off regardless and I hadn't discovered this forum yet.
 

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Discussion Starter #9
I was also wondering about the cam lobe. I couldn't fit my smallest feeler gauge in the intake valve (.03mm I believe) before adjusting it. That little "bowl" beneath the sump screen was filled with chunks and mettalic paste mess. Some were fairly thick slivers, but not nearly as thick as a gear tooth, I don't think. Trying to bend them and manipulate them indicates they are a very hard material. Plug is black and caked with cooked oil.
 

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Your only option right now is too is to pull the cylinder and have a look. Whether you guess it right or not, it still needs to come apart to fix it.
 
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Hey...07keo02Welcome to GC from Wisconsin.

I can't really tell anything from the pic's you posted..sorry.
From what I have read I would start with pulling the clutch housing off and examining the oneway and the wet clutch and clutch housing bearings. The WC and the OW are slip, grab, hold, slip and release parts. They are subject to a lot of wear.
 

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Discussion Starter #13
Had a few more looks with the camera. I think the oil control ring is probably broke, along with some other potential things. Going to do a top end and take a look at the one way in a month or so. Too many projects at the moment and this one is low on the list. Thanks for the insight.
 

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Discussion Starter #14
A little old but figured I'd update how this turned out. When putting a new piston in I had the timing chain slip off the bottom gear.

Turned out it was a blessing in disguise as I found out the left engine cover bearing was missing half of its cage. A definite source of magnetic slivers in the engine. Hopefully the only source.
 

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The final conclusion, specially with pics helps the next person. Great job, and a Great machine, definetly worth saving.
 

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Thank you for the update & definitely worth keeping in the back of the mind, would suggest a couple of early oil changes to snag any metal slivers that snuck past the strainer.
 
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