Rattling sound under hard throttle

[vinman]

Hey guys and gals,

I need some help on possible causes of a rattling sound I have heard a couple times now when quickly opening the throttle (while rolling already). The bike is perfectly normal when riding at an average pace. But in the last week there were two instances where i went from about 1/3 to 1/2 throttle to almost wide open and I heard a rattling sound, almost sounded like a bell ringing. It only lasted a couple seconds. There's nothing loose on the bike, teh bike rides fine, and one of the times it happened I didn't have the saddle bags mounted. So that eliminates bags or anything in the bags. Any ideas? I'm supposed to bring my bike in to the dealer tomorrow to get fault codes checked, throttle bodies synch'd, and real drive seal replaced.

[Arbreacames]

Your bike is pinging. Give it a higher-octane fuel. If you are already using premium, stay over 4000 RPM in hard accelerations.

[gerrywide]

Sounds like PING to me ... use higher octane fuel or maybe add a little octane booster to your next tank of gas and try it out.

[NHighCotton]

I've heard this same thing on mine and it's not pinging.

It does sound like a bell ringing. I've noticed it after I removed the muffler and installed a short tailpipe (big bags both sides), I hear it in 5th and 6th only, at a not yet determined RPM.

Beats me, I was thinking it's maybe from the cat?

[dwayne]

I've heard this same thing on mine and it's not pinging.

It does sound like a bell ringing. I've noticed it after I removed the muffler and installed a short tailpipe (big bags both sides), I hear it in 5th and 6th only, at a not yet determined RPM.

Beats me, I was thinking it's maybe from the cat?

I have the same problem, almost sounds if though somthing is loose. Doesn't sound like pinging at all, at least in my case it doesn't.

[vinman]

Its not the cat, I replaced it with a staintune collector box last June. I put on 12,000 miles since swapping the cat for the collector box. I've only heard the ringing sound a couple times so far in the past couple of weeks. Maybe it is pinging. Maybe I should try a different gas station? I've been using Exxon 93 octane. I;ve always used premium fuel.

I can't remember if I was below 4,000 rpm or not.

[boxermania]

vinman

If the sound was noticed on either 5th or 6th gear the sound is definitely pinging as you are "lugging the engine" drop down to 2nd or 3rd gear and proceed to do the test again and see if you hear the noise.

Your bike might have also built up some carbon....do you normally run the bike into the "happy zone" 6,500 to 7,500 rpm?. These motor's being aircooled and lazy (lots of torque) tend to build up carbon if not cleared every so often.....so go out there and run her to redline on the lower gears a few times and everything will be allright. These bikes run better when you run the peass out of them.........

Make sure the oil level is OK......

[dwayne]

... "happy zone" 6,500 to 7,500 rpm?...

That is rather high don't you think? Might clear carbon buildup but at what cost?

[Capt. Blackadder]

... "happy zone" 6,500 to 7,500 rpm?...

That is rather high don't you think? Might clear carbon buildup, but at what cost?

Fifty cents worth of gasoline?

[rpd1]

Mine does the same from time to time. Just spend some time in the upper rpm's and it will fix itself.

Ryan

[dwayne]

... "happy zone" 6,500 to 7,500 rpm?...

That is rather high don't you think? Might clear carbon buildup, but at what cost?

Fifty cents worth of gasoline?

True, but of the engine I think running that high in the RPM range would be bad for the motor. Sure you can do it, but how short will the life span of the motor be? Everyone likes to say their bike is the best built, that the motor was made for that, but I am no engineer...well mechanical, but I do believe that running the machine at that kind of engine speed will certainly shorten its life.

[Rootin55]

I think he means to run it up to redline (bump the rev limiter) through a few gears on occassion, not to cruise at 6-7K RPM's miles on end. They need to be blown out periodically.

[disonny]

Mine did this too, and it sounds to me like pinging. I asked the dealer about it and he told me if the valves are out of adjustment it could make that noise too. Try adjusting the valves and see what happens. I know mine was better after I adjusted them.

[bearsfolks]

Mine has always done this "rattle" thing too, full throttle at about 4,000rpm. I can't buy the "carboned up" argument because of the fuel injection and tendency to run lean, not rich. If there is any carbon build-up it must be from burned motor oil, not fuel. I used to worry about it, but the "cures" sounds worse than the problem.

[NHighCotton]

Being an Airhead rider I believe I know the difference between "pinging" and "ringing".
This is harmonic at 3500 rpm in 6th gear, and if someone thinks this too is lugging the motor, they're mistake about that also.

[vinman]

Mine did this too, and it sounds to me like pinging. I asked the dealer about it and he told me if the valves are out of adjustment it could make that noise too. Try adjusting the valves and see what happens. I know mine was better after I adjusted them.

Hmm, I might try adjusting valves. I adjusted them 4 weeks ago and took my sweet time about it making sure I did it right. Maybe one came out of adjustment? The service rep at the dealer said to downshift. I wish I could remember what gear and rpm I was in at the time.

I haven't run up to the redline in a long while. Whether that has an benefit or not I don't know. But I like the idea! So I'll give it a go.

[vinman]

I picked my bike from the stealer today. They did a throttle body synch and fixed a rear drive seal leak.

While on the highway I opened teh throttle hard at about 3800 rpm - heard teh ringing sound. Then I did it again at about 4200 rpm - no ringing.