View Full Version : Engine chatter at 3500 rpm

08-19-2003, 04:08 PM
Hey Tuono experts:
I've been browsing this forum for some time, and can't believe the wealth of useful tips you guys share. This is my first post, and I'm desperate for some help here because I'm not getting any answers from the local dealer (ExIm...)
I picked my Tuono up in June, and I've had the 600 mile service performed as well as the derestriction (kept stock can, went with Aprilia eprom 1063003).
The problem is, whenever I accelerate, either moderately or aggressively, in any gear, from 3500-4000 rpm I get a bad rattle noise from the engine. Don't know if this is valve chatter or what, but it is most disconcerting. I've had riding buddies tell me they hear it and wonder what the heck it is. I reported this to the dealer, who supposedly synchronized the throttle bodies, checked the valve clearances (yes, and they were reported just fine), and did the de-restrict. He claimed that they couldn't notice anything, but as it turns out the test rider only put 0.8 miles on the bike. The derestriction didn't help either. What gives? This thing sounds/feelsl like it may come apart! (PS - I've had several twins, including a Duc and an american made twin) Please help !

08-19-2003, 06:54 PM
If there is a cure for this I would like to try it too. Meanwhile, I learned to leave with it. Either it bothers me less and less, or its going away.

Ted in Evanston
08-19-2003, 07:11 PM
You're pretty close to the AF1 boys in Austin - why not take it to Ed & Micah?

08-20-2003, 06:08 AM
IMO the V990 has not been designed to rev lower than 3000-3500 and if you drop the rev lower than that you'll make the engine totally unhappy, making all kind of noises and rattles.

The low inertia flywhell could be an explanation for this...:rolleyes:

08-20-2003, 08:12 AM
mines not that bad, but i do try to ride all aprilias above 4k

08-20-2003, 09:15 AM
I think I may have noticed this a bit at low revs..I think it may be the couterballancers but not sure..I seem to have read an article where they mentioned they could hear the counterbalancers every once in a while...mine has a slight knocking sound at low revs every now and then...I've never really thought twice about it..good luck..

03 tuono
01 ex2fity

08-20-2003, 12:35 PM
I had it out again last night, I guess I should clarify that the chatter comes in anywhere from 3500-4000 but is VERY prevalent thru 5000 rpm. I guess I'm still debating if something is wrong or if the engine is damaged. I just can't accept that its something to learn to live with.
Hoping someone else had experience with this and knew what it was / how to fix it ??? before I take it back to a dealer.:confused:

08-20-2003, 12:38 PM
thats definitely not what mine does..mine does it when its at idle and I blip the throttle a bit..but no noise once off idle...wonder what that could be??

03 tuono
01 ex2fity

08-20-2003, 01:41 PM
that doesn't sound good- definitely try to get in touch w/ one of the real experts-AF1, as has already been mentioned, or the guys at Evoluzione.

Micah / AF1 Racing
08-21-2003, 08:47 AM
I am not sure what the exact cause of this is either but with my Mille the magic number was 3,800 rpm...everything smoothed out there and she would pull clean and smooth through the rest of the rev range. To me the simple and 27,000 mile effective solution was to always operate the motor at 3,800 rpm or above. I think it has a lot to do with balance factors....to make the engine smooth in the uppper rpm range you sacrifice a bit of smoothness down low....since these bike happily rev to 10K I think the comprimise is of little nusciance.

10-07-2003, 11:00 AM
Hi guys, I might be a little late on this thread but I am having a rattle at 4,500-5,000rpm's. My '02 Mille has less than 6K mi on it, is not low on oil, has been serviced, and makes this loud rattle just about every time I ride it. I am thinking it is the cam chain :confused: Strangely enough, I hear it most while going around left-handers. I guess the noise is coming from the left side of the motor making it more prominent when I am hanging off the left side of the bike. Hmmm.

I am going to bring it into Scuderia so they can test ride it and see what's up

10-07-2003, 06:34 PM
Have you guys checked your chains? It sounds like chain slap, if you can hear it more in left turns..maybe the ground is reflectling the noise so you can hear it better.

The reason I say this is because of riding next to my buddy's Tuono with his chain loose, I could hear and see the chain "slapping" the swingarm when he was at lower revs. I think it's because of the power pulses being spaced out more on a twin, it's like it sends shockwaves through the chain at lower revs. ???

10-07-2003, 10:32 PM
This is a bit late too.But I had this problem after my first service.Any thing under 3800 - 4000 rpm I had pinging.I have a bit of nitro. drag racing input so I checked my spark plug gaps,I won't get to tecko. about why & how.But my plugs were set at 8 mm,which is wrong.I set mine to factory rec. settings = 6mm - 7mm.Now it only does it if I'm lower than 2800rpm or 3100rpm up hill.
Check a rear plug first they are easier to get to.
All the best to all.

10-08-2003, 08:39 AM
I have to update the status from my original post.
After some more miles, changing sprockets, removing air restrictor, baffle and cutting the wire (to access the alt map) it must say it is almost gone. There still a little bit of it, but almost cannot be heard unless you are really paying attention. Or is it that I tend to spend less and less time on those rpms :D

10-08-2003, 08:54 AM
Whick dealership did you get your bike from? Just wondering, I used to live in San Antone

10-08-2003, 09:03 AM
I bought my bike from KC International.
check them out at www.kc-international.com
Had a great experience buying the bike, and overall the dealership is top-notch.

I haven't had any service done there yet, though. Had the service done somewhere else. That was probably my mistake.

10-08-2003, 10:25 PM
Big V twins do have bad manners at low revs due to the few power pulces per crank revolution and low fly wheel inertia effect. My Tuono Racing clatters at 2500 rpm and lower in any gear with not much more than idle throttle position. It's also easy to lug these engines because of the low fly wheel inertia. Poor fuel mapping can contribute/aggrevate this problem. When this happens the chain will slap the swing arm violently causing the clattering sound. You will notice this if you dyno your bike. It's the trade off for a quick reving engine. Lowering your overall gearing will help it be more streetable with little loss of top end speed. I'd make the dealer go thru it with fine tooth comb to insure there is not a problem internaly. I got mine from Eximport as well and can say I,m not real happy with them. I'm going to haul my bike to AF1 if I need work beyond my abilities.

10-09-2003, 11:11 AM
I'm going to stop by Scuderia as soon as I get a chance. My rattle is at 5K rpm while rolling on. I am fairly certain it isn't my chain. Thanks for the heads up though. I want to lower my gearing one of these days.


10-09-2003, 07:57 PM
That sounds more like a stuck open or defective cam chain tension adjuster.Another member posted a while back about his being stuck open and when he pulled it out it had some oily gunk stuck in it stopping it from working correctly.

10-13-2003, 11:20 AM
Originally posted by Scary
That sounds more like a stuck open or defective cam chain tension adjuster.Another member posted a while back about his being stuck open and when he pulled it out it had some oily gunk stuck in it stopping it from working correctly.

That's what it sounds like to me. I just need to find time to get to the shop. Thanks for the info.

02-10-2004, 05:44 PM
FLatBlack, I have exactly the same thing you described in your first post... around 4500 rolling on funny vibration clatter sound, sounds towards the front of the bike to me and definatly more prominant on left handers with out a doubt. Getting a 16tooth front sprocket put on at weekend so will let you know if its cleared up!!!



Isle of Man