1980 Suzuki GS850G mystery noise

[Guest]

Hey guys!!
So about a little over a year ago, I bought my first bike! A gs850g
HISTORY:
I tried craigslist and called a couple mechanics to see if they had any advice or cheap bikes for sale, finally I found a Harley place that had my bike for sale, only a grand!
I was off the wall excited to make this bike my own. Little did I know, until a year later, that I bought what some would call a "roach".
Although I rode it off the lot the issues came quick.
"Oh they all leak oil"-The seller
I had to replace the stator, starter relay, majority of fuses, battery, tires within the first couple months.
I didn't have any problem doing that but vowed to never go to that Harley guy again.
I took off the gas tank and rear fender to paint, got some new clean bars, put some aftermarket gauges on it.
Around 4 months after purchase I notice (im pretty sure) a head gasket oil leak, and a little grime around the valve shims.
Dropped it in LA traffic,
Got new bars, (and a bar end mirror)

This brings us to Thanksgiving time 2015, I tried everything and couldn't get her started.
No matter how many times I ran down the driveway she wouldn't stay running no matter how much gas(or choke) I gave.
Once again I looked to the web, using the lovely posts on thegsresources I figured I had a clogged idle jet.
I was excited to dive deeper into dismantling my bike and taking on new challenges. (Never done a carb cleaning before)
Watch some youtube videos on how to clean inline 4 carbs and BOOM.
She was purring, smoothest throttle response since Ive owned her.
Christmas time 2015- I notice a tapping or clunking noise when at low RPMs. I can put her in 5th gear and cruise around all day, but in low gears and low speeds, the engine just doesn't sound right.
I thought cam chain, or maybe the shims should be checked, but honestly I have no clue.
I took an audio recording of a little run down the block if anyone would like it let me know and I can post it!!
Maybe I am being paranoid, or maybe not.
Also thank you all for helping me over this last year, I have had a great deal of fun (and learned alot) on my scoot thanks to all your posts!!!!!!

IMG_3158.jpg
(Audio Clip: https://clyp.it/srs0cesa) you can hear a jangling noise, that is my keychain, the noise I'm trying to solve is the tank like twaping noise, thwap thwapthwapthwap. You can hear me call out the RPM throughout the clip too.

[fred smailes]

I have an 81 850g 70,000kms the motor has/had a clicking sound at idle.
Bothered me at first but it never got worse, rode it hard, it is always strong
Did gaskets down to the barrel base a couple years ago now. Didn't see anything unusual, no metal in the oil never touched the valve settings but I think the noise is gone. Haven't ridden since fall so not sure.
Have no clue what it is/was.
Fred

[Brendan W]

One man's clunk is another's ticking. Very hard to be definitive without hearing it and even then the sound quality of most posted files is............
Anyway there are a few noises these machines make. One is the high frequency, sewing machine, ticking of happy valves. Another is cam shaft end float walking back and forth across the head. Doesn't seem to do any harm except irritate owners.
I suggest you check the security of the clutch basket. The big nut loosens ( all by itself ). Open the oil filler. You should be able to see the clutch basket with the tabs on the plates in the slots. Pull the clutch in. The plates should shift outwards but is the basket moving a bit with them. Put the bike in first and rotate the back wheel back and forth just enough to take the slack out of the drive. Is the basket moving in and out as you rock back and forth. Mine was moving a few mm.
On the other side of the bike the starter idler gear between the starter motor and the clutch should have a washer on each side.They are tricky to fit and easy to lose. If that side has been open a PO could have gotten lazy, careless or both. On mine both were missing. Things quietened down another bit after they were replaced.
Cam chain tensioner function and noise can be investigated by rotating the tensioner wheel counterclockwise a very small amount with the motor running. If everything is good you start to hear chain noise and then it disappears when you release the wheel. I suggest you read up on this and the associated risks before attempting it.

[wind jammer]

I concur with Brendan. My 1100e when idling in neutral with the clutch released mad a loud banging noise. You would swear it had a rod knock. Pull the clutch handle in and would quiet down. I pulled clutch cover and pressure plate. I found springs out of spec and nut holding basket loose even though the tab was bent down to hold it in place. Took nut off to check for damage and looked ok. Put loctite thread lock on nut and torqued to 50 ft lbs and bent tab back down. Plates looked good and were in spec so reused them. Put new springs and gasket checked oil level. The noise is gone and clutch works great!

[eil]

I don't have anything to add about the engine noise except that sometimes a low-rpm ticking or knocking ends up being a loose screw or bolt somewhere. (Possibly not even on the engine.)

Understand that almost any older bike you buy is going to need to get caught up on maintenance, even if the seller assures you that it already is. (Because either they are lying, or they are not but you have no way of knowing which.)

All those things you listed (and then some) are standard maintenance items. If you haven't rebuilt the brakes, checked/adjusted the valve shims, swapped all of the fluids, replaced the regulator/rectifier, and bought a new petcock, put those on your todo list as well.

These 8-valve GSes are some of the most reliable and long-lived bikes ever made if (and only if) they are given some minimum of care.

[Vmass]

I heard a strange noise early on in your clip, some type of clicking and I have no idea. However, it may just be the recording but it doesn't sound like all 4 cylinders are firing.

[Jarrett]

Wow thanks guys!! Big help, now I have a small to do list.
Would it be worth it to rebuild the camchain tensioner?
I will definitely be checking the clutch plate nut. Cause your clutch experience is just like what happens when I ride.
As far as I know all cylinders are working, in Dec. I checked all plugs and I was getting spark.
Could I be getting spark but the cylinders arent firing?
I will be replacing the plugs come spring time.
Thanks again guys!