Tlted_Jelli

XS650 Enthusiast
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Hello All,

Just recently purchased a 1983 XS650 that had been converted to a hardtail bobber here is South Jersey. No idea how many miles are on the bike. So far as I can tell it has an XS PMA Charge System and a Pamco Ignition installed with the mechanical auto-advancer. Looks like the frame is aftermarket and not a hardtail kit (its stretched, super low, and no weld/cut marks). The PO put BS38's on it that i had to put 6 Sigma jet kit in to run UNI Pod filters after doing an ultrasonic bath in berryman's chem dip. Anyway, I got it running and started to notice that famous whirring noise. (like someone spinning a crank flashlight)

I did all the searches here and saw the 3 most likely candidate: starter gear not disengaging, main crank bearings, and a worn out cam chain guide.

I decided to try the screwdriver to the ear stethoscope test and it definitely seemed to be louder on the top end right between spark plug and the ignition cover/cap. So I took out the filter on the cover and lots of metal shavings. Dropped the sump filter pan and found lots more shavings (in the oil too) and a strip of black rubber or plastic. To me this says from what i've read that its the cam chain guide that is the likely culprit.

I saw this post: https://www.xs650.com/threads/cam-chain-guide-replacement.37649/

So i've got a cart from Mikes XS with:

1x Front Cam Chain Guide Stopper (05-0006R)
1x Complete Athena Gasket Kit (201-0020)
4x Brass Cylinder Head Sealing washer (01-0651)
1x Copper Top End Washer kit (18-0870)
4x Camshaft Bearing(05-0007)

I've also got a Haynes Manual on the way since the clymer's doesn't cover 1983

Not sure if I'm missing anything on the parts list as I'm a newbie to working on bikes. I saw from the post I linked to, he spent a lot of time cleaning his piston head and cyclinder walls. I was hoping to not have to remove the complete top end but if I'm getting at the crank wont all the gaskets need replacing anyway? Should i just order new piston rings as well? Any other recommendations or comments for a newbie? Thanks in advance. Pictures and videos of the above described linked below.

I figure while I have the engine off I'll check for crank wobble as well.

Video of the bike idling and video (close up) where you can kinda hear the noise
 

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Please check the shavings if they are magnetic
And show the amount of black plastic
I don't believe it is the cam chain guide. Making the sound
There is a thread here on the sounds Jetmechmarty has a video of the worn cam guide sound
The whining sound there is Info perhaps

https://www.xs650.com/threads/1978-xs650e-standard-consistent-whining-engine-sound.54000/

Thanks for the reply! It looks like from that thread that it was his chain guide that was the issue. I actually read through most of it earlier. I'll be going back out tomorrow to do more stethoscope tests and check for the wobbles. I'll also look up the jetmechmarty sounds.

The plastic piece I found is in one of the pics. It's about an inch long and like a toothpick mostly rubbery. I can say whether the shaving were magnetic or not I blew them away. There was a lot like in the thread you posted on the right side cover filter. I put a pic of that as well
 
Your cam chain adjuster looks to be very tight. I don't see any in-out movement on the plunger. That might cause a "whirring" sound. I'm hoping you had the cover nut off the cam chain adjuster to check things and hope you're not driving around all the time without it, lol.
 
Thanks I'll try adjusting the tension again and yes the nut was just off for inspection. It was something mentioned in another thread before but I did not know about how it should travel +-1mm while running when tensioned correctly
 
I'd suggest not to run it any more as that amount of metal in the filter means significant damage. Pull it down & repair it before any more happens to it.
Yeah I was pretty worried when I had seen that as well. I'm just trying to assess what is going on before committing to completely tearing apart the engine. At least id like to isolate it to either top or bottom end.
So far plan for tomorrow is to adjust chain tension properly. Turn it over with the starter (plugs out) and watch the tensioner pin for the right movement and the PMA rotor for wobble.

Run it again bearing the result of the previous for a minute or two and listen for any change. If there is no change I'll probably remove the oil and right side cover and watch that side for wobble and check the starter gear.

When I drain the oil I'll check the flakes to see if they're aluminum or not this time. I figure aluminum means the chain guide? Steel and magnetic could mean something much worse?
 
Thinking out loud here
The bike is misfiring on the left side 3 rd video
The lower filter has some metal .. A bit to much
The upper has more than I have ever seen so Mr Dunc in # 8 perhaps has the final outcome
But if that filter has never been cleaned it perhaps can look lite that
There can be a metallic sound there not sure but first impression is that it should be more rattling metallic sound.

I would check the valve play so it is not off on the left side at least and get the cam chain adjuster moving.
I suspect the rotor wobble.

If the adjuster starts moving and the whirring disappears Please do another video outdoors lover RPM
and a little blipping .. Both sides ..Perhaps can hear if excessive play somewhere.
I cant hear it now ...
 
Thinking out loud here
The bike is misfiring on the left side 3 rd video
The lower filter has some metal .. A bit to much
The upper has more than I have ever seen so Mr Dunc in # 8 perhaps has the final outcome
But if that filter has never been cleaned it perhaps can look lite that
There can be a metallic sound there not sure but first impression is that it should be more rattling metallic sound.

I would check the valve play so it is not off on the left side at least and get the cam chain adjuster moving.
I suspect the rotor wobble.

If the adjuster starts moving and the whirring disappears Please do another video outdoors lover RPM
and a little blipping .. Both sides ..Perhaps can hear if excessive play somewhere.
I cant hear it now ...
I'll be sure to do another video and an update after tomorrow's testing. I'll add checking the valve clearances to the list after getting the tension correct.
Also note the 3rd video was from before I had adjusted the timing and jetted the carbs
 
So today in just the last hour or two I went back to the bike and took off the left side cover and crown/ cap nut on the cam chain tension adjuster. Spun the rotor around CCW a couple times and loosened the tensioner until i could see some in out movement. After i had some movement i spun it around until it was at its furthest in point and tightened it back most of the way leaving it poking in still less than an 1/8" from flush. Spun by hand some more to verify it still had movement.
Fired it up...and clutch pushrod popped out with a bunch of oil coming with it...DOH!!!

Other than that had nice movement on the pin and the top end whirring is gone. Now however, since i had the cover off it seems the whirring is coming from the xs charge PMA rotor (or abouts that area)

Did the screwdriver stethoscope again and while there is still a metallic clicking coming from the top end. the whirring is most definitely from the rotor. I even checked the sound center front and back of the lower engine case with the screwdriver stetho. Seems to be the PMA rotor now. Same deal the tempo increases with throttle blipping. I believe before i had the chain tension way too tight and i was getting a noise from both the rotor AND the chain guide. Seems i may have eliminated one. I also checked the valves and they are in spec.

You'll also notice in one of my videos that the electric start doesn't always catch right away and in the photos you can see MAGNETIC metal flakes. Didn't get that right side cover off today but im now thinking maybe the plastic/rubber and flakes are from the #4 gear???

Also let me know if you see different but i dont see any wobble (did videos of the rotor with engine running and with just the starter) Also check out that backfire! Timing is probably a bit off right? I also think i have it way too rich (black wet plugs) gonna turn in the mixture screws a bit.

An interesting note regarding the rotor. Its supposed to be a 17mm retainer nut but that doesnt fit. A 3/4 "fits" but wont go deep enough on the nut for me to use my torque wrench. I noticed this when i attempted to spin the rotor and the nut came loose. Something tells me it was never torque properly to begin with. It looks like the rotor itself may not be centered properly as the 3/4 socket wont go onto more than the outerlip of the nut unless i cock-eye it.

Either way i think my plan moving forward is to get that rotor off and see if i can re-seat it proper. I will also plan on sooner rather than later getting the engine off and tearing it down and getting a look at everything with the justification being replacing the #4 gear and the front cam chain guide.

Sorry for the long post. Fealt i owed you all a solid update after you gave me all the advice. I will keep them coming until the issue is resolved.




 

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Thinking out loud
Not that bad running -- Some sounds .Whirring is there
But there is to much metal at the magnet and in filter
it can be hard to find inside but to keep on running I believe will / can cause damage that is not there now if you are lucky.
I have not heard of 4 th gear as a problem .It is usually second gear or first .But 4 th can of course happen
Some inspections can be done with the motor still in the frame
Oil pump clutch.
Compression test and perhaps shift through the gears listening with the wheel in the air.
But it looks -sounds as a tear down .But it is a big job and can cost some money
Depending on other things this summer riding can then be off

Post # 8

I'd suggest not to run it any more as that amount of metal in the filter means significant damage. Pull it down & repair it before any more happens to it.
 
Thinking out loud
Not that bad running -- Some sounds .Whirring is there
But there is to much metal at the magnet and in filter
it can be hard to find inside but to keep on running I believe will / can cause damage that is not there now if you are lucky.
I have not heard of 4 th gear as a problem .It is usually second gear or first .But 4 th can of course happen
Some inspections can be done with the motor still in the frame
Oil pump clutch.
Compression test and perhaps shift through the gears listening with the wheel in the air.
But it looks -sounds as a tear down .But it is a big job and can cost some money
Depending on other things this summer riding can then be off

Post # 8

I'd suggest not to run it any more as that amount of metal in the filter means significant damage. Pull it down & repair it before any more happens to it.
Thanks Jan_p. I was referring to the starter gear. But you are right I need to get a gasket kit and open the right side cover an check some things before completely tearing it down
 
Your little round side oil filter looks odd, like it's been "painted" with something. That would effectively plug up the screening and render the filter useless. It should look like the screening on your bottom sump filter. Now hopefully, the by-pass would open so oil could flow, but if not then that may explain all the metal chips. You may be getting very little oil to the topend and it could have self destructed.
 
I think when the front guide is gone it makes little if any sound. Mine would make a faint sound when i tilted the bike so the side of the chain rubbed the side of the channel. Check for a separated crank, which is what it sounds like to me in the 1st vid. Pull the wire from the coil and turn the motor with the starter and look at the ends of the crank for any wobble
 
@5twins @xjwmx
I finally got a garage to do it all in. Setting up to tear down the engine. Gonna crack off the right side and watch for wobble again on the crank on that side. Check the gears for wear and a starter gear grind. Re-seat the PMA rotor on the left side just in case since it's clearly not centered from what I saw from my last big post.
That should give me a starting point on what to purchase first go.
Didn't have much time today after work and moving everything to the garage. Only had time to raise it a bit and drain the oil again
IMG_20220228_201243178.jpg
 
So I took off the ride side cover and it looks pretty dang clean. Only thing is a gear behind the clutch basket has some wobble (video) not sure which gear this is. Still gotta take the clutch apart but my harbor freight impact screwdriver is crap. Gonna go get a Quinn which I heard were good quality.
The oil and whatever on the rear oil plug was gelatinized

 

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