Oil Nozzle OK... What else causes low rpm rattly sounds?

[3XW_LOGIC]

So my 3XW was making a garagarakarakara sound on low rpms which led me to doubt the oil nozzle on the starter as suggested by some previous experiences here and on the xjr forums...

Have adjusted my idling to 1200rpm and I don't hear that sound often

But, for mental safety, Took out the nozzle and found it in pristine condition

No rubbing of the chain on this so far. Some minute manufacturing scratches that can be seen aren't by the chain (different angle)

So...

What else could cause a sound that I can best describe as "garragarr" when the idling is set below 1100RPM or when I'm halfclutching slowly from a stop without revving up much?


Next thing I'm gonna try is to see some other parts suchas the starter one way clutch

 (seems fine though, as when I drive the engine backwards by using the nut on the spark timing pickup side it rotates the starter, but the engine moves smoothly immediately disengaging the starter clutch when moving in the normal direction.)

Well then I tell myself, I'll just live with it... But it bothers me to not know.

I've new cam chain tensioner and guides installed and that didn't change anything.

I also took the clutch out to see if the damping springs behind it were bad, but they seem solid, nothing jittery there.

I'm in the process of checking valve clearances and I have discovered almost all valves clearances are in spec or at most 0.01mm on the loose side..
(on a cold engine, overnight)
Still, im going to do the shims and see if it makes any difference. Then do some carb balancing...

Next I'll try to see if there's some other parts that can potentially cause a rickety rattly feeling at low rpms (I really don't want to open/split the case as a longrride is coming up though)

Any suggestions on what else i can look at (without splitting the case?)

(ready to live with it, but just trying to do some safe easy investigation into this issue)

[Pat Conlon]

Well now that's a puzzle....how many miles are on your engine?
Our starter chains stretch, just a fact of life.

Could you be hearing a clutch plate chatter?
Did you remove the wire snap ring and cushioning spring from your clutch pack so you could convert over to a 7 wide clutch plate set up?
Is the clutch basket secure? No wobble or run out?

Try removing your cam chain tensioner, inspect it, make sure the compression spring has full range of easy motion, if ok, reset it and reinstall it.

That's all I can think of...

Pat

[3XW_LOGIC]

Thanks Pat

I'll go through the suggested Clutch and tensioner checka later this week one by one and post an update.

To answer your question, I have about 55000 km on the bike (which to me is quite young in my opinion).

And it's in superb condition.
When I had taken the  head off a year ago to change the head gasket and rubber thing as there was a tiny oil seep on the exhaust header side, and the cylinders were all beautiful clean, no scratches, honing marks still visible, the cams are super beautiful too (the previous owner was definitely changing the oil often and driving well before somehow being abandoned for a year or two).

It's like a rocket and has the full power. Plugs were beautiful too. Responds well to all (normal and crazy) driving inputs.

I have a new tensioner, nice fresh tensioner mushroom head, and new spring, maybe I'll try pushing one click more? Is that recommended. If may have messed it up while installing it initially. I installed in its shortest condition and then added the spring from behind. Maybe I'll add it in the shortest condition, use some tool to click a notch, and then add the spring. Not sure whether this is right but some others seem to have done this before.

About the clutch, no I still have that pesky wire thing and the narrower clutch plates and springs. I guess I'll get rid of those and put full size ones on.
The friction plates are thick still and have plenty of life in them though..

Next im going to look at the accessories parts near or on the engine, like the generator, the starter motor, etc. That rotare with the engine. I have an XJR1200 too so maybe try interchange parts to narrow down possibilities.

Is the generator known to get rattly? Does the engine run without the generator in place? For testing only of course (Or does oil start spewing out crazy ...) same thing with the starter motor - maybe I'll somehow start the bike and the pull the starter motor out haha. (probably not recommended)

Although I'm beginning to think It could simply be the carburettor not properly in sync at idle. It purrs like a cat at 1200 but still, I've anyway ordered adjust shims and so I'll do a carb retune after i do the valve clearance adjustments.

I had a nightmare that some part of my chassis is cracked and is making that sound. Was scared and checked the chassis in the morning, obviously nothing wrong with it (at least in all the visible parts) lol

Hope I get to pin the issue down soon....

Happy Riding!!!

[T Legg]

If your carbs are out Synchronizing them can make a big difference . I put a new motor in recently and it ran great from 1/4 throttle on up but at idle and low rpms I could hear a regular rpm related thumping noise and feel the vibration or Harley like shake. It was much better when the clutch was disengaged and the transmission stopped spinning in nuetral. I swapped the entire clutch assembly with one from another of my bikes with no change in sound or vibration.
 By then I thought it must be the transmission. Before I was going to do anything drastic I decided to check the compression, recheck the valves and balance the carbs.
 I was surprised the sound and vibration dissappeared compietely. Now my bike runs strong and smooth from first cracking the throttle to w/o throttle.
 I adjusted the valves last in the winter and wether due to the heat or sloppy adjustment the last time, I had several  tight valves . I think what really solved the problem though was the carb synch . Carb #2 was way out of synch .

[3XW_LOGIC]

If your carbs are out Synchronizing them can make a big difference . I put a new motor in recently and it ran great from 1/4 throttle on up but at idle and low rpms I could hear a regular rpm related thumping noise and feel the vibration or Harley like shake. It was much better when the clutch was disengaged and the transmission stopped spinning in nuetral. I swapped the entire clutch assembly with one from another of my bikes with no change in sound or vibration.
 By then I thought it must be the transmission. Before I was going to do anything drastic I decided to check the compression, recheck the valves and balance the carbs.
 I was surprised the sound and vibration dissappeared compietely. Now my bike runs strong and smooth from first cracking the throttle to w/o throttle.
 I adjusted the valves last in the winter and wether due to the heat or sloppy adjustment the last time, I had several  tight valves . I think what really solved the problem though was the carb synch . Carb #2 was way out of synch .

Thanks for sharing this.

This gives me more reason and hope.

I'll do a proper carb sync and post an update!!! (as soon as my shims arrive coming week)

[Pat Conlon]

Perhaps when you reinstalled the head you mis installed the cam chain tensioner?

https://fjowners.com/index.php?topic=5620.0

If the growling sound you hear is chain related, there are only 2 chains in the FJ engine and we know the starter chain isn't the issue.