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08 450f engine "rattle" just off idle

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Hello all.... Just bought a used 08 450f and I've noticed a rattle type sound from the left side while just coming off idle..in pretty much every gear...the bike seems to run fantaastic...tons of power and just had a dealer check over including valve check...just wondering if anyone has any ideas or if its a known issue... Thanks for any and all input..

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Assuming correct chain tension, it's common for the condition of the chain and slider to cause a rattle like noise as the chain cracks and sends a backlash load through the transmission when you are at lower revs. I think it's a form of harsh mechanical resonance. I've had it many times over the years. A hooked front sprocket is bad, as is a chain with worn pins or bushes which has too much sideways movement. A new chain and sprockets often fixes it. A badly worn slider can contribute too. When you fit a new slider be sure to put a nice bed of silicone adhesive (clear) between slider and swingarm, as a sound dampener.

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If it does it when in neutral then check if the cam chain adjuster is working correctly , if only when riding then more than likely what Numroe said .

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Main bearings, main bearings, main bearings. How many hours are on it? You can pull the flywheel or have the dealer do it and look at the cage that holds the balls in place. If it is deformed you found your problem. You or they can do this without any parts, just reuse the metal backed gasket for the ign. cover and lay the bike on it's side as to not loose the oil. Also I replace my cam chain every time I put a piston in it. It's amazing how much noise they make over time that you don't even notice until it's new again.

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Like that silicone bead trick numroe,getting ready to put a new slider on will be sure to do this.

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Like that silicone bead trick numroe,getting ready to put a new slider on will be sure to do this.

Yep good idea, But I cut a piece of rubber gasket material you can get from autozone and add that under a new TM slider. No chain slap noise either. This is after the insulators that come with a TM slider wear out from moisture.

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hmm so had the bike out for a few rides this weekend...noise is still there...i think it might be from the chain gaurd...the upper block sorta rattles in the mount..... gonna look for a new chain / sprocket / slider and go from there..almost positive that its not an engine noise...wouldnt worn main bearings rattle even more under load??.. thanks for all the input so far people..

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hmm so had the bike out for a few rides this weekend...noise is still there...i think it might be from the chain gaurd...the upper block sorta rattles in the mount..... gonna look for a new chain / sprocket / slider and go from there..almost positive that its not an engine noise...wouldnt worn main bearings rattle even more under load??.. thanks for all the input so far people..

It's just chain slap. Silicone the slider in place till you get the new one.

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