XJ11 Question Weird Noises

[Eric_XJ]

So on the freeway today about 65mh and I hear almost like a whistle or squeal from the front of the bike. If I back off the throttle it quits, but on the throttle hard and it continues and the pitch goes up slightly...any thoughts ?

[CatatonicBug]

Is it like an air flow whistle, or more like a high-pitched rattle?

[Eric_XJ]

More like a whine. Closer to an air flow whistle. But if I let of the throttle it stops.

[CatatonicBug]

I'm just guessing here, but maybe a small exhaust gasket leak?

[COOL TOM]

Noise

Check your speedometer, that what was the noise on my XJ. Just disconnect the cable and see if the noise guits.

[XSokieSPECIAL]

Sounds kinda like to me your just hearing gear whine from the transmission.

These things have straigh cut gears and are very stong but really whiny when your on the throttle.

Nature of the beast..........FWIW

[Eric_XJ]

Sounds kinda like to me your just hearing gear whine from the transmission.

These things have straigh cut gears and are very stong but really whiny when your on the throttle.

Nature of the beast..........FWIW

I thought the same thing on my ride home from work today. Sounds like a manual transmission in a old honda civic. Lots of whine and noise. Just wanted to make sure it was not anything out of the ordinary.

Thanks !

[XJOK2PLAY]

The only other thing I might add to check would be the little vaccuum plugs on each carb port.... I put all new ones on less than a year ago, 2 had already rotted the ends off, and was causing a vac leak, and it created a distinct whistle going down the highway you could definitely hear... JAT

[Eric_XJ]

The only other thing I might add to check would be the little vaccuum plugs on each carb port.... I put all new ones on less than a year ago, 2 had already rotted the ends off, and was causing a vac leak, and it created a distinct whistle going down the highway you could definitely hear... JAT

that was next next place to check. I have a issue with it wanting to hold idle between 2k-3k rpms and I was leaning towards vacuum leak for that issue. I got a good deal on the bike so I can't complain about the little things. I do want to tear into the carbs. The PO said that the PO before him had Filter pods, the exhaust and possible had the carbs jetted. The PO put a factory airbox back on, but gave me the pods with the bike. If it is jetted, I will probably go back to the pods since it's running rich right now. I want to sync up the carbs and find out what the deal is.....

[XJOK2PLAY]

Hey, Eric...
Yeah, it might pay to check 'em out...

I replaced mine, rode it for about 25 miles, and noticed it again... found it had rejected the new port plugs I had just installed, and gotten rid of 'em!
Ports were wide open!

Found some much heavier, thicker type port plugs, and that stopped that!

What idle speed are you setting it at?
on an XJ, it should idle at 1100-1200 rpm.
I recently decided to bump mine up to 1500, though... so my turn signals will continue to flash at stop lights...

I figured you meant when you'd accelerate between 2-3000, instead of idle...

I had LOTS of issues for a while with the idle & performance of mine until I got the carbs synched right. Mine would stall on launch, change idle speed constantly... you name it. Drove me crazy. Carb setup, airbox & jetting, and exhaust combo's are critical. One affects the other. On the XJ, I found the best dependable combo is to stay pretty stock. Only mod I've made was adding a Dynojet kit, which REALLY helped me, once I got the needles adjusted properly. Now my bike starts great, idles right, never stalls... runs like a champ. I love it.

[Eric_XJ]

Hey, Eric...
Yeah, it might pay to check 'em out...

I replaced mine, rode it for about 25 miles, and noticed it again... found it had rejected the new port plugs I had just installed, and gotten rid of 'em!
Ports were wide open!

Found some much heavier, thicker type port plugs, and that stopped that!

What idle speed are you setting it at?
on an XJ, it should idle at 1100-1200 rpm.
I recently decided to bump mine up to 1500, though... so my turn signals will continue to flash at stop lights...

I figured you meant when you'd accelerate between 2-3000, instead of idle...

I had LOTS of issues for a while with the idle & performance of mine until I got the carbs synched right. Mine would stall on launch, change idle speed constantly... you name it. Drove me crazy. Carb setup, airbox & jetting, and exhaust combo's are critical. One affects the other. On the XJ, I found the best dependable combo is to stay pretty stock. Only mod I've made was adding a Dynojet kit, which REALLY helped me, once I got the needles adjusted properly. Now my bike starts great, idles right, never stalls... runs like a champ. I love it.

I just picked up the bike today, so I have not had a chance to change any settings on the carbs. I picked it up by trading my 82 xj650 for it straight up. I was excpecting to have a few issues with it, but besides the idle issues, it runs really good. Feels great on freeway and the pipes don't sound too bad. i have a feeling they will be better once the carbs are adjusted properly. I can smell fuel and it backfires and pops on decel, so I figure it's running real rich right now. I had to play with the carbs on my xj650 and the carb sync procedures look very similar so it shouldnt be too bad. Just gotta tear her apart

[XJOK2PLAY]

Yep... mine popped on decel too, until I went back to a good stock exhaust, and got the carbs set up right.

Yamaha did their homework when they matched all their parts up... it's hard to outdo the stock setup... which is unusual for anything else!

One recommendation for synching... use a good 4 vac guage setup w/ the little adjusting screws in each vac line to settle the guage shakes.
When tuning, try to get your highest vac readings possible as you adjust, and try to make them all balanced w/ one another as close as possible.

If you just concentrate on equalling them all w/ one another only, and your vac readings are low, it still won't be synched right. The plates may be opening the same, but the mixture adjustments won't be right, and it'll perform accordingly. It WILL effect idle, popping on decel, stalling on launch... you name it. XJ's use a vac switch unit under the gas tank to convert from vac into a voltage, which is sent to the TCI unit under the seat. This is how it advances timing. So, vaccuum levels are very important on an XJ for proper timing advancement. Timing advance is totally different on the XJ's compared to the XS's.

There's several recent threads about this where we've discussed it...
DAMHIKIJD...

HTH's ya get going. Sounds to me like you made a great 'trade up'!!
Regards,
Bob

[draketrumpet]

I get that same whine between 40-55 in 4th gear, maybe 5th, can't remember. I figured it was the tranny since it came and went with more throttle. Usually need to be around 3500+ for it.

[XSokieSPECIAL]

I agree with Bob on the sync. That should square away the idle.

I don't know anything about XJs other than what I've read here, but don't you have to disable or remove the YCS to sync.

BTW....when you get vac caps get them a size smaller than it takes and use a little WD 40 to slip them on and they won't get blown off when you get that occasional intake burp.

[Yahman]

I agree with Bob on the sync. That should square away the idle.

I don't know anything about XJs other than what I've read here, but don't you have to disable or remove the YCS to sync.

BTW....when you get vac caps get them a size smaller than it takes and use a little WD 40 to slip them on and they won't get blown off when you get that occasional intake burp.

Yes, the YICS system needs to be disabled in order to synch the carbs. For that you would need the YICS Eliminator.

If you can get the little clamps that go over the vacuum caps, they won't pop off either.

Larry