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Discussion Starter · #1 ·
View attachment cb360oilpumprotor.pdf
Hey Everyone,

I need help identifying the loud low knocking noise coming from my engine. I'll give a bit of a back story as to what happened to give you the relevant information. I've included a video of the bike making the sound as well.

It all started when I turned the engine over with the oil dipstick not secured, on an angle. (Yes, it was very dumb.) I chipped 7 teeth off the oil pump idle gear and a small chip in one tooth on the primary drive gear. (see the exploded view in the photo)
I replaced the oil pump idle gear with a new one. removed all the chipped material and cleaned the whole right side of the engine really really well.
I also flipped the primary drive gear so that the chip no longer contacted the oil pump idle gear. The chamfered side is now facing outward. (it says in the manual to be careful to install this the right way but after very close inspection it doesn't seem to be an issue if it's flipped. and it's out of the way of the idle gear. (if anyone knows for sure that this is a total rookie mistake, let me know)

So I replaced the gasket put everything back together and started it last weekend and got this noise. (see the attached video)

A friend at work said possible crankshaft or crankshaft bearings? He had a grave look on his face meaning not good. I was hoping to sell this bike but I want to know what's wrong and figure out if it's even worth anything anymore.

Is it pooched? Is it fixable? Can I get any money for this thing?
Any advice or help addressing the sound I'd really appreciate it.

thanks
 

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Sounds like it's running on one cylinder. If it's a rod the sound should change when you pick the throttle up off idle.
 
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Discussion Starter · #4 ·
Flip the primary gear back where it is supposed to be and see what happens.
That would require having to build the chip up with weld on the primary so the oil filter idle gear doesn't slip over the chipped tooth. And also a new gasket.
I'm thinking for all that trouble I'll just source another gear.
Before I do that I want to see if anyone knows for sure what that noise sounds like.

I appreciate the suggestion, thanks
 

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Discussion Starter · #5 ·
Sounds like it's running on one cylinder. If it's a rod the sound should change when you pick the throttle up off idle.
It's idling a little rough right now for sure. I'm getting exhaust out of both exhaust headers though, so both cylinders are firing. I have pretty low compression right now also making it hard to idle any lower that about 1400 rpm.

you're saying the rod of the crankshaft would sound different if that was the issue?
 

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Lets get honest here. How long have you had the bike, how many miles have you driven it and when was it last driven?
What specific work has it had in the past year, does it currently have oil and has it been driven low on oil?
How does the oil slinger look?
How long have you let it idle/driven it with this noise?
 

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Sensei
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Why do you suppose the manual would SPECIFY to install the primary gear chamfer inwards if it wasn't a necessity?

.... A required clearance for correct spacing is the only reason I can see necessitating the chamfer inwards......

If the gear does not properly torque down to capture the bearing inner, could the crankshaft try to rotate within the inner race essentially using its ID as a NOT too well lubricated steel on steel plain bearing, instead of rolling on the balls???? (just a weird random thought as to what might be occurring...Doode is probably closer to the truth....)
 

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Start it and rev it like that a few more times and you'll likely figure out what the knocking is... That said, I've actually heard the cam chain make pretty much that same sound. May just be adjustment.
 

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That's not the cam chain... and it's not a rod either, it isn't often (repetitive) enough to be a rod. I think it's in the primary drive and I think J-T and Steve are on the right track
 

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If it was my motor, I would remove the valve adjustment covers and confirm oil is reaching the top end. The rhythmic sound might be due to gear lash from the reversed drive gear meshing with high spots then low spots on the adjacent gear. Another possibility is something loose contacting the clutch housing behind the side cover.
 

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Sensei
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I'm still betting that the slight misalignment from being installed flipped and the metal deformation at the chip pressuring the larger clutch primary gear are the cause of the noise......
 

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Discussion Starter · #13 ·
I'm still betting that the slight misalignment from being installed flipped and the metal deformation at the chip pressuring the larger clutch primary gear are the cause of the noise......
Thanks for the advice. I had a mind not to flip the part but I was feeling confident at the time it would work. It was merely an urge to fix it now as opposed to have to wait any longer. I'm still pretty green at all this (clearly).

I'm going to order a new part and report back when I've got it all back in place. Hopefully with good news.

thanks
 
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