Low rpm knocking/clunking

[Vloukole]

Good day

My GS550E recently developed a low rpm knock/clunk which can be felt and heard while riding.
It only starts when taking off and stops around 3500rpm in any gear.
It does not happen when the bike is cold.

I recently replaced the cam chain tensioner gasket and when I released the plunger, the knob was stuck so the plunger did not shoot out with a lot of force. I did not immediately notice and drove the bike for 2 miles.
The bike still runs great. The knocking started halfway through a 50 miles ride.

I checked the clutch hub nut and torqued to spec.
The knocking/clunking does not change with rpm when in neutral.
Drained the oil and checked for metal. Nothing.

Any idea what it can be or where to look?

Thank you in advance

[Chuck78]

The noise does not change with RPM changes when in neutral? That is a very very peculiar and odd symptom.

[Vloukole]

The noise is only present when I moving in gear at low rpm.
I managed to feel it just now when coasting with clutch pulled in at low speed (10mph).
Could it be the chain? Maybe binding cause there is sprocket wear on the sides of both sprockets.
Im going to check my wheel alignment.

[Chuck78]

Yes, chain stiff links, same problem I'm having.

If it does it with bike stationary, in neutral, you need to check camshaft timing IMMEDIATELY

[Rob S.]

If the chain is very loose, it can slap against the swing arm.

[Vloukole]

Checked the cam timing. All good there.
Wheel alignment was pretty far out. Adjusted it using the string method. Also adjusted the chain tension with a friend on the bike. The chain was previously adjusted while on the centerstand. When my friend got on the bike, all the play in the chain disappeared. It creaked. I then adjusted it with him on the bike.

I took the bike out for a ride and there was no knocking sound or feeling. Hopefully that was the issue and fix.

[Chuck78]

Inspect the chain real good. I had a buddy's bike making atrocious popping noises after adjusting the chain when he ran it extremely loose for a month or more. turned out the original chain's o-rings fell apart and left a lot of slop side to side in the chain, and the links were going half sideways due to all the slop, sitting diagonal instead of straight, popping back & forth...

And yes, swingarm near horizontal is the tightest position for the chain. when the front sprocket, swingarm pivot, and rear axle are all in a straight line with each other is the tightest point. Always need to check tension when someone sitting on the seat and bouncing it with their weight on it. Way worse than too loose. although both are very bad.

[Vloukole]

Will inspect the chain. Thank you Chuck.
The bike has 15k miles. Do you think it is time to replace chain and sprockets?
Both sprockets show some wear on the side.Both have a shoulder on the side.

[Chuck78]

The bike I mentioned probably had about the same miles on it, it had 7,000 when I helped him buy it... Rubber and neoprene o-rings & seals, as well as gaskets only last so many decades before they are compromised, including the o-rings in your original chain.

luckily for you the GS 550 came stock with a 530 chain, which is what everyone converts their 750, 1000, 1100 Suzuki GS's to as all of the bikes larger than 650 got the big heavy clunky 630 chain, the 530 runs much smoother, and modern 530 chains are stronger than the original 630 chains anyway.