Faint Ticking sound at acceleration

I have a very faint and subtle ticking/clicking sound that you can only hear when riding the bike. It does not happen at idle, even when I rev up the rpms. I checked all the exhaust collars to see if it might be an exhaust leak and they're all securely on. Any ideas what might be going on? Thanks.

Josh

 

Are you hearing this noise over the normal valvetrain noise?

 

thanks for responding. Not sure what you mean by valvetrain. I'm probably confusing you by saying faint sound but it is subtle. It happens the second I take off in first. And like I said it only happens when I accelerate. So, I could be riding along at a steady 40mpg and not hear it but as soon as I open the throttle the ticking happens. I should also say that it intermittently will happen when the bike is idling but most of the time it's doesn't. It's very unpredictable but what's interesting is that when the sound does happen at idle the sound will disappear when I lean the bike over on the sidestand but return when I put it straight back up. It almost doesn't seem like a very big deal but of course, I don't want to completely ignore it in case it's indicative of a bigger problem down the road.

 

When the valve clearances are set correctly you should hear a steady tick, like a sewing machine.
That will happen at all engine speeds.
There also is a tick that some of the XJ 650 and 750 engines have which is caused by slightly wide cam endplay (just makes noise, not a problem otherwise).

The fact that the sound goes away when you put the bike on the sidestand makse me think that you anve some other issue.
It would help to know what model, sub-model, and year XJ you have.

 

Sure. It's an 81 Yamaha Xj550rh Seca.

 

OK. One thing that comes to mind is the normal tick from the primary chain.
The 550 has a hydraulic primary chain adjuster, and those can be slightly slack, allowing the chain to tap against the adjuster.
I'm not a 550 expert, so I can't say wether how the sound changes for you is normal, but I do know that it's mostly eliminated by bumping the idle speed up to around 1500 RPM.

 

under load, makes me think cam chain adjustment. slack gets pulled to the back and rattles around

 

Awesome. Is this as simple as adjusting a screw somewhere or do I have to take it in? Will it affect the function of the bike if I leave it alone?

 

Another thing to consider but might be completely unrelated is that in the far right carb diaphragm there is a pin hole which I will be replacing. Any chance this could cause a ticking sound?

 

go to a hardware store and get a bottle of "liquid electrical tape" clean the top side of the diaphragm with some window cleaner and put a dab on the hole, let it dry good and your set.
no that won't cause a tapping sound but it needs fixed

 

Awesome. Thanks.

 

The idle speed adjustment knob is behind the carbs, right in the middle. Turn it clockwise to increase the idle speed (after the engine is fully warm).

 

thanks. I've adjusted the idle speed quite a bit and settled at 1500rpm. Is adjusting the idle suppose to help the ticking in some way?

 

If the ticking is coming from the primary chain adjuster it will pretty-well eliminate it. Bumping the idle up a bit increases oil pressure enough that the hydraulic adjuster will take up all of the primary chain slack.

 

Tried it. Still ticks on acceleration.

 

Speaking of idle, when I rev the engine from an idle standpoint the rpms are just a tad slow to come down but not too slow. Just enough to be noticeable. I heard this could be caused by a mixture that's too lean. Since the problem is extremely minor I thought about just going to each mixture screw and turning it maybe a 1/4 turn more on each carb. Is this a good place to start?

 

This should cure the slight hanging idle.
A synch should be done after this though.

 

From my experience, I recommend making mixture changes in 1/8 turn (thickness of a dime), then test the bike, then adjust again as necessary.

As stated, you will need to resynch after adjusting mixture since out of synch also seems to affect "hanging" revs.

 

Ah jeeze. Since I don't know how to resynch nor do I have the money to get that done right now, should I just leave it alone? Is a hanging idle bad for the bike. Like I said, it just hangs for a second then goes down. It's more annoying then anything.

 

Weull, I might suggest that you could adjust idle mixture without needing any special tools, but of course you won't be able to resynch. However, you could allways turn the mixture screws back to where they were?

 

Synch is pretty easy, and can be quite cheap if you make your own manometers.

How To: Make a 2 bottle synch tool

The tick could be realted to the hanging idle. When the carbs aren't in synch you can end up with two or more cylinders essentially "fighting" each other and creating an imbalalce that might make a bit of noise.

I would definitely check the cam chain tension as Polock suggested, since that can also cause noise, but go away once the slack gets taken up (if the tensioner is not too far out of adjustment).

xj-550-cam-chain-tension-adjustment.5666

And as I think I suggested before, some tick/slap noise at idle is normal for a 550.

knockin-but-fades-with-rpms-chain-primary-noise-xj550.26358

 

if you have a noisey 550 set idle to 12oo rpm this will help pump oil to nozzle and primary chain. gets nice and quite

 

Very good point. thank you.

 

I just looked at this thread and realized I never answered the question to the ticking noise. It was an exhaust leak caused by the mufflers being welded to the swing arm. Who knew. The ticking would only happen when I sat on the bike which was so confusing. It caused a bending in the exhaust just enough that it opened a little hole somewhere every time I sat on the bike. Thought I'd share. I feel like I bought the most booby trapped Seca 550 out there. Cheers!