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Discussion Starter #1
So I just bought this bike (2003 v star 650 classic) last week and it came with the loud knocking sound, looks like from the front cylinder. I adjusted the front cylinder valves but the sound still exists. I also changed the oil filter and oil. When I engage the throttle, the sound increases with it. Any ideas?
Here is a video:
Loud knocking sound video
 

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Super Moderator "Loose Nut"
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Hard to tell exactly in video, but sounds like loose rocker arm. Here's a video that might help confirm valve adjustment.
 
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Discussion Starter #3
Hard to tell exactly in video, but sounds like loose rocker arm. Here's a video that might help confirm valve adjustment.
That's The video I watched when I adjusted the valves. I only adjusted the front cylinder valves, since that's where it seems the knocking is coming from.
Would incorrect valve clearance on the back cylinder cause knocking in the front cylinder?

I also took out and inspected the chain tensioner and it seems good. Cam Chain seems good too.
Both pipes get hot so I am getting sparks in both spark plugs.
 

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2001 Yamaha XVS650 Dragstar Classic and 1999 Honda NT650V Deauville
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Not saying that is the case here, but people have been known to mix inch and metrics and ended up adjusting the valves with way too much clearance.

An exhaust leak can also cause weird noises. Whatever your issue is, it seems related to rpm.
 

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2006, Yamaha, Royal Star Tour Deluxe
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Hi, for me this is a problem with the assembly of the piston with the rod, means that bolt is knocking... or worse, the bolt from the assembling of the rod with the crankshaft...
Hopefully I'm wrong...:confused:
 

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2009 650 classic white
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OK it sounds like a waaayyy loose rocker arm. Did everything look ok inside the valve covers? Next are you sure you had it on top dead center when you adjusted the valves? I would suggest open the valve covers again and turn the engine over by hand and try to see what is going on. Grab the rockers and try to wiggle them. You should only get a tiny bit of movement when the valves are closed ,like.004 to.006"
It does NOT sound like a rod to me. If it was a rod it would really hammer when you reved it!
 

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Discussion Starter #8
OK it sounds like a waaayyy loose rocker arm. Did everything look ok inside the valve covers? Next are you sure you had it on top dead center when you adjusted the valves? I would suggest open the valve covers again and turn the engine over by hand and try to see what is going on. Grab the rockers and try to wiggle them. You should only get a tiny bit of movement when the valves are closed ,like.004 to.006"
It does NOT sound like a rod to me. If it was a rod it would really hammer when you reved it!
It was at TDC, the dot was lined up with the notch. I double checked the valve clearance. The rocker arm has a bit of side movement, besides up down movement, when at TDC. Should it have a bit of side movement?
 

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can you confirm if you had the front cylinder timing mark aligned when you set TDC?

98749
 

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Side movement is OK.
Something is making that noise,it is not a normal sound.
Instead of a stethoscope ,use a screwdriver, handle to the ear, point on the engine, to track down exactly where it's coming from.
Maybe the rear cylinder?
Maybe a loose cam chain? Throwing out suggestions, you're not alone in this ,I'm just trying to help.
 
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