Weird noise from engine?

Hey guys, so I recently check and adjusted all the valve clearances! I was riding it a bit around my property and I noticed a metal rattling sound on the right side of the motor, I can't tell if it's from the top end or bottom end! I was cruising slowly in first gear and it didn't sound too good! It's been ok until now! I'm gonna re check all the valve clearances but is there something else that could cause this? I'm worried about anything going on in the bottom end!
The bike is a 1984 xj650!
Cheers!

 

Make sure that all the screws that you got loose are torqued to spec. Also check any parts that you may have loosen up to get to the valve cover.

 

What he ^ said. Also check for missing or loose exhaust stud nut. FWIW there are no '84 650's.

Gary H.

 

There are 1984 XJ 650's. They were not sold in the North American market, and went out of production in '85.

 

Go figure. I thought something like that...well you know, right after i posted. Thanks for the info. Where's the "delete" a post button?

Gary H.

 

Don't delete. Own your mistakes. A lot of people have learned from mine


Back to the matter at hand. Is the noise like a rythmic tap, or is it more staccato. like a chain rubbing?

When you did the valve adjustments, were any shims changed on the right side? Did you make sure that the shims were fully seated in their buckets before putting the valve cover back on?

 

I did change most of the shims, I noticed this noise before I did the shim job but was and is intermittent. The best way I can describe it is that it sounds like metal rattling but doesn't seem to do it constantly. I will re check my shim job for sure as soon as I get a bit of time to do so. Is there anything in the lower portion of the engine that could cause what I've described that I could check or test fairly easily?
Thanks

 

As far as the year, I questioned the ownership when I first got it cuz when I typed in the year at online parts places I couldn't find my bike so I learned how to decode the VIN and apparently I have an 84' and I am from Canada! Who knows where the bike was purchased tho!

 

Gonna attempt to post a video!

What is this sound?:

 

One of two things: one of your valves (I'd say an exhaust valve because the sound is louder in front of the engine) is now too loose because you put the wrong shim, or you have a blown out exhaust pipe gasket causing a leak right at the engine. Both give similar sounds.

 

Blowing exhaust gasket on the right?
or
Cam shaft end float which has become more pronounced now the valves are in spec? Is it slightly louder when on the side stand?
Does the tapping go when you increase the revs above 2k?
A mechanics stephoscope or long scredriver held to the ear should help narrow down where its coming from.
My 550 has a noticable but intermitant tapping that disapears above 2k revs. It started this when the valves were put in spec (the engine was way to quiet before). Ive checked and double checked valve clearances, the cam chain, exhaust gaskets etc. There was a Yam bulletin years ago about excessive cam end float and how a better machined centre cap was the cure. They also said only to do it if the customer complains, it has no detrimental effect on the bike. This applied to both 550s and 650s.

 

Well, I really don't think that it's the shims because I went smaller and the noise wasn't there before! I will check for exhaust leak, can anyone recommend a good way to do that? I'm thinking to just spray something while running!

 

If you have a punk left over from lighting fireworks you can use that. The smoke will visibly blow away from the leak when you get the smouldering punk near to it.

 

It doesn't sound as bad when I hit 2500 rpm !

While revving!:

 

I don't even know what a punk on a firework is! Lol

 

A punk is a stick made of material that smolders (males a fair amount of smoke too) instead of burning. You can use a blown out match or candle as well.

Listening to the video I hear a very rhythmic tapping, which is indicative of the camshaft endplay TSB that was referred to earlier. If it were an exhaust leak the noise would not be covered up with an increase in engine speed, instead it would get louder.

My 750 has the same tapping, and I know that the camshaft endplay is near the outside of the specified limit, so from my perspective you are good to go; nothing to worry about. Your idle speed sounds high to me though.

 

This is good news as I'm not quite as worried now but a little annoyed cuz I like a nice smooth sounding engine! Idle speed is a little high, I seem to always be playing with it! Thanks a bunch for the input man!!
Cheers!

 

"Well, I really don't think that it's the shims because I went smaller and the noise wasn't there before!"

Smaller shim = more clearance = more noise.

Remember these valve specs tighten up rather than loosen (unless there are other issues!) so by fitting smaller shims you will increase the valve train movement. This would (well I have convinced myself anyway) allow more movement/endplay in the cam itself as a by-product. A tiny amount, granted, but enough. I bet if you put all the old shims back in it would be as it was before. I was so paranoid with mine that I even dropped the oil expecting to see chunks of metal or at least glitter in the oil. Of course there was nothing.
Tight valve clearances will make the engine nice and quiet right up to when it burns a valve out

I would go along with what k-moe said and dont worry about it if the bike otherwise runs fine.

 

The smoothest engine I've ever had the pleasure to operate was a 1978 Mercedes diesel. Valve clatter can be a very sweet noise to hear, and that engine provided a symphony of clatter.

 

Lol! I had an old honda car like that also!

 

I know its a different bike, but the nephew and I finished up a Suzuki 650 this summer for him. I has the cam float problem and in Suzuki's it is a lot worse then your video. Once we get it warmed up and riding at higher rpms it goes away. The first time we heard it I thought we had a rod knock. Tore things apart and "fixed" things and its still there. The guys on the GS forum assured us it wouldn't be a problem. He's been riding it all summer and no issues.

 

Cool thx for the post! I'm feeling more comfortable about it now! I thought I had a bottom end problem at first! Scary! Lol

 

Ok so I decided to take this bike for a short cruise to cycle through the gears and to see how she rode!
I could still hear this noise while cruising through the gears! This video was taken just after cruise! I've been hearing what everyone says but my gut is goin squirly! Can the guru's pls listen to this vid and confirm in their opinion this cam end noise situation?
Cheers!
Sounds bad after a short cruise!:

 

That sounds much more like the primary chain rattling around to me. It is a very different sound than I heard in the first video.

 

It sounds like a sloppy idle to me. I remember my Maxim-X sounded like that when the carbs were not balanced (or synch'ed) properly.

 

round here somewhere you'll find a how-to for adjusting the cam chain by Rick-o-matic, do that. then take care of the lumpy idle, do a running sync and tweek the mixture screws.
once it's running smoother a lot of that noise will go away

 

Ah, it's project time looks like! Is it possible that the chain is making noise now cuz of the shim job? I ask cuz I never heard that noise prior to that! Mind you I also never took it past 1st gear in my fairly long driveway! Time to search some how to ' s!
As far as the sloppy idle goes, the bike came with a K & N air filter, could that affect the idle? I've not messed with the mixture screws and only checked butterflies with a pin!

Thx for the awesome help guys!!
Cheers!

 

Having trouble finding a how to for the cam chain adjustment! Can anyone help out with this that has better searching skills than I? Thx

 

http://www.xjbikes.com/forums/index.php?threads/the-information-overload-hour.27544/

- CAM CHAIN TENSIONERS:

The secret life of cam chain tensioners can be explored further at:

http://xjbikes.com/forums/index.php?threads/24597

and

http://xjbikes.com/forums/index.php?threads/28447


Yamaha specifies that for the manual-tensioner models, the adjustment should be checked and adjusted (if necessary) every 5,000 miles. Automatic tensioners should never need checking, as they should adjust themselves, well, automatically!

Here's some tips on how to go about doing this adjustment properly:

http://xjbikes.com/forums/index.php?threads/23008


And here is a very nice visual, so you can understand how it actually operates:

http://xjbikes.com/coppermine/displayimagepopup/pid=7682/fullsize=1.html

 

Thanks Chacal , I just noticed my XJ900 has the automatic tensioner!

 

Thanks chacal! Very much appreciated!
Cheers!

 

Ok, so after reading through the info Mr chacal so graciously posted for me, I think that I may have an automatic tensioner which I think I cannot touch it! Now I'm a little stumped thinking that it needed an adjustment to help with this noise!
I've attached a pic so that someone may confirm this for me!
I guess my question is now, what's my next step for this noise?
Thx!

 

On a bit of another note, I'm gonna make a vacuum sync device to sync the carbs and was wondering what I should do with the vacuum line that goes to the petcock? Should I remove it and run it on the prime position? Or should I tee into it with the Guage? I expect that would change the reading tho, no?

 

You'll have to remove the tank to do the sync. If you use the tank as a auxilary tank remove the vacuum line and put the petcock on prime when running your bike. Turn it back to on when it's not running. Use the rubber cap/clamp for the vac port you are testing to blank off the port the vac line goes to (usually #3).

 

Ok thx! I was also wondering if it was necessary to do all of them at the same time? Is it possible to measure the vacuum with a Guage of each carb individually?

 

per RickcoMatic 2011:
The Bolt with the Lock Nut that you incorrectly adjusted ... is the "Lower Rear Cam Chain GUIDE Locking Nut"

If you think your Cam Chain needs adjusting, ... you have to Manually present the slack in front of the Tensioner and have it Automatically adjust to pick-up the slack.

Pull the Plugs
Remove the Left Side Crank Cover.

(Have an assistant help you. Let then "Tap" on the Tensioner with the Butt-end of a Hammer Handle while you Manually present the slack before the Pawl.)

Place a Wrench on the Flats and slowly Jack-over the Engine CLOCKWISE for 2 Full Revolutions ... steadily turning the Engine and moving the Chain DOWN across the front of the Rear Guide.

After Turning the Engine over 2 Full Turns ...
Come to a SLOW and STEADY =>> STOP!

(Your NEXT move will present the Slack in the Chain in front of the Tensioner.
Here's where you Cue the assistant to "Drum" on the Tensioner end,)

Swiftly Jack the Engine over COUNTERCLOCKWISE ... Moving the Chain UPWARD across the front of the Rear Chain Guide.
As the Chain reverses direction, ... the Slack will be presented before the REAR CHAIN GUIDE, ... and the TENSIONER will expand a notch or two to tighten the Chain.

You may have to repeat this procedure a few times to have the Pawl take-out all the slack.

 

I didn't incorrectly adjust anything! I thought I understood that if you have an automatic tensioner that you couldn't adjust the tension and I was just trying to confirm this!
I'm only looking into this cuz there have been some thoughts that thus could be the cause of the sound coming from my motor!
This process your explaining I think might be over my head as I don't even understand the terms, pawl, drum on tensioner end, lol damn noobs!

So in this process I don't need to line up the c and loosen the 2 nuts?

 

Not necessary but a lot faster. I use a 4 gauge set up. Yes, you could use one gauge to sync but it'll be time consuming. A lot of members use a two gauge set up.

Gary H.

 

You have an automatic cam chain tensioner. Polock was quoting Rick from another post. The comment about the incorrect adjustment wasn't referring to you.

Much of the noise should quiet down once you synch the carbs. I wasn't aware that you had not done that yet. Without the synch the cylinders are fighting each other because of the uneven fueling between them. That causes some sharp, sudden vibrations during each revolution of the crank, and that can make a bunch of really bad sounding noise (some of which is the cam chain, and primary chain being jerked around).

 

When you're ready to start sync'ing your carbs don't forget to run a big fan in front of your engine, to keep the engine as cool as possible.

 

"pawl" google it, it's the thing in your ratchet that makes the clicking sound.
"drum on tensioner end" change that to "tap on tensioner end". that's to rattle things around in there so the "Pawl" can snap into the next tooth and hold the chain tighter
your automatic chain tensioner worked great 30 years ago and it depended on spring tension. after 30 years that spring could be tired and that procedure will give it a little help.
that bolt the other guy turned, if your interested, holds the cam chain guide. it's plastic so the bolt gets snugged down on it and the lock nut gets tightened, you don't have to mess with it.

 

Oh, oops to Polocks post! Lol
I think I will do this first as I can wrap my head around this!

So correct me if I'm wrong: to sync the carbs I make sure the bike is cold, put a fan on it to keep it as cool as possible, attach the sync tool, set main idle to where I want it and then adjust air mixture screws to even out carbs? The other thing im wondering is the Po had a K & N air filter in it, will this affect the sync process?
Thx for your help!!

 

understood! Thx!

 

Will do, thanks!!

 

Sorry for misreading your previous post!
This makes a little more sense now! I think I'm gonna go through the sync'ing process first and see where that lands me! Kinda wish my bike had the manual tensioner, seems so much easier! Lol!
Thx for your input! !

 

Just wanted to say thanks to everyone on this forum! I have been on many forums for car related things and this has been by far the most helpful one! I've only had a motorcycle for the last couple months of my life and I've learned so much which has all come from here!!
Cheers to you all!!

 

So correct me if I'm wrong: ok to sync the carbs I make sure the bike is cold, really it should be warmed up, 10 minutes around the block, put a fan on it to keep it as cool as possible, the fan is to keep it from over heating, attach the sync tool, set main idle to where I want it the idle will change as the sync changes and then adjust air mixture screws to even out carbs? go thru the sync process first The other thing im wondering is the Po had a K & N air filter in it, will this affect the sync process? no

 

To synch the carbs you don't adjust the mixture screws but the synch screws.

Mixture screws are on top of carbs, you use them when you "colour-tune", meaning adjusting the air-gas mixture according to the colour of the flame inside the cylinder (special tool required).



and synch screws are here:

 

sync tools, each one has it's own details.
gauges, they bounce around a lot unless modified. and need to be verified
long tubes on a board, if the sync is way out they can get sucked out quickly, very quickly sometimes.
carb stix or any of the ones you buy, cost too much.
2 & 4 bottle, tend to be bulky and they can break (glass).
i use the 2 bottle, i did use the long board but needed the board for something else

 

You should sync carbs #1 and #2 first with the first sync screw on the right on the picture, then sync #3 and #4 with the sync screw on the left, and then you sync both pairs with the screw in the middle, by matching the readings of #2 and #3.

Idle should be set around 950 rpm when you begin the process and set at 1100 rpm when finished.

Now you understand why two guages make the process a lot faster.