Engine noise---a bit long---sorry

[gasbag]

Hello,

My bike, George, has developed a problem and I was hoping someone might have an idea as to what may be wrong.

It is hard to explain. It is an engine/tranny rattling sound but it is not specific to engine speed, meaning it doesn't get louder as speed increases and the noise does not change pitch. It is always the same sound. The noise occurs at certain speeds but does not increase in frequency or loudness if I accelerate. The noise sounds like it is coming from under the front of the tank, maybe down low. My pipes aren't obnoxious but they are not stock and I can plainly hear the noise riding with a helmet. I had an old Triumph TR4 that had a loose timing chain tensioner. It sounds a bit like that only not as loud.

The noise occurs ONLY at these times; the speeds are approximate.

1st gear: 14 to 18 mph
2nd gear: 24 to 28 mph
3rd gear: 34 to 38 mph
4th gear: 44 to 48 mph
5th gear: 54 to 58 mph

NOTE: in between those speeds the engine sounds perfectly normal.

As I run up the gears the noise gets more noticeable. I assume that is because as the bike gets up to cruising speed everything is quieter and the noise becomes more apparent. In first gear it is hard to hear.

If I am cruising at 56mph in 5th the noise is very apparent. If I pull in the clutch the noise goes away as I coast down the road. If I re-engage the clutch the noise returns. Also, if I decelerate the noise will change a little and get a little louder.

My dealer found a compnsator sprocket loose, whatever that is. They said they tightened it. No change.

This noise is so speed specific I can actually ride around and avoid hearing it just by altering my shift pattern.

I don't like bothering people with my problems, but this noise has me stumped, and obviously my dealer at the moment. Any help or suggestions or like experiences would be much appreciated.

Thanks for listening.

Have a good day and ride safe.

gasbag (Larry)

[Backroad Mike]

It's a Harley, they all do THAT.















Sorry, couldn't resist.

I'm assuming you've check the exhaust studs/nuts for tightness?
Looked the engine over for ANYTHING caught in a tight spot, dropped a screw??

[TalonChief]

What RPM are you doing at those speeds? My front exhaust rocker clatters like hell from about 23-2500 RPM. It measures well within tolerance, but still makes noise.

[gasbag]

Originally Posted by TalonChief

What RPM are you doing at those speeds? My front exhaust rocker clatters like hell from about 23-2500 RPM. It measures well within tolerance, but still makes noise.

I have no tach. All I have are the speeds at which it occurs. It is odd that it occurs at and around 15, 25, 35, 45, and 55 mph. It also disappears if I disengage the clutch at those speeds.

[TalonChief]

You're probably turning about the same RPM at those speeds. IIRC, my bike changes about 10 mph/gear range at a steady RPM. I'd listen to the heads. It's a common noise on TCs.

[y2kflhr]

you may wanna check motor mounts, and do a general nuts and bolts check, did this happen before the tire changes?

[YankeeBob]

Your bike is named George? The noise is probably him complaining about you constantly teabagging him!

[Geezer-Glide]

Ok, It's RPM specific. I can think of three things right away to check. Two are going to take a COMPETENT mechanic to check.

A) Exhaust shields. As the engine RPM hits a certain harmonic, it can cause a vibration that will make all sorts of noise. Check them. Check the entire exhaust system. Look for broken mounts, loose mufflers, loose baffles in the mufflers.... just don't look, touch, poke and hit stuff with your hand.

2) Primary chain tensioner shoe. The dealer SHOULD have noticed something amiss with this when they torqued the comp sprocket. SHOULD have....

14: It's a softail, right? Check the engine balancers. This of course requires getting deep into the motor.

Do you have any vibrations with the noise?? Any "buzz" that you can feel??



Get back to us as you progress in your search.
Good luck Grasshopper.

[Geezer-Glide]

Originally Posted by YankeeBob

Your bike is named George? The noise is probably him complaining about you constantly teabagging him!

This from a guy in New England.


BWAHAHAHAHAHAHA!!!!!!!!!!!!!!!!!!!!

[Geezer-Glide]

Originally Posted by YankeeBob

Your bike is named George? The noise is probably him complaining about you constantly teabagging him!

Speaking of which, you coming to New York to the bike show Saturday??

[YankeeBob]

No. A little far. Besides, daughter is home from school, so Dad/Daughter time is very valuable right now.

[gasbag]

Originally Posted by Geezer-Glide

Do you have any vibrations with the noise?? Any "buzz" that you can feel??

Get back to us as you progress in your search.
Good luck Grasshopper.

No vibrations at any rpm. Runs very smooth. The ONLY symptom is the noise.

My son is coming down this weekend. He is going to ride it and tell me what he thinks. He is a darn good mechanic and almost as good looking as his old man. We are also going to go over the whole bike with a fine tooth comb.

The one thing that really bothers me is that the noise goes away when I disengage the clutch. But then again I am just your average idiot when it comes to mechanics etc.

Originally Posted by y2kflhr

you may wanna check motor mounts, and do a general nuts and bolts check, did this happen before the tire changes?

It began when the bike was returned from the shop. They had installed a tuner and did a dyno tune. Before that, no noise.

This was before the tire installation. Fixing the noise was suppose to be part of the service during tire installation.

[Geezer-Glide]

Originally Posted by YankeeBob

No. A little far. Besides, daughter is home from school, so Dad/Daughter time is very valuable right now.

Yep, it sure is. Mine are grown now and only a few miles down the road. With our schedules, we don't see each other as much as we would like. Take advantage of every second!!

[vafatboy]

The first thing I would check is the primary chain tension. If they were just in there for the compensator then I would suspect something in the primary before I went looking elsewhere.

If the compensator was loose enough and ridden for a while, the teeth on the rotor for the stator get rounded off and it will rattle too.

I wouldn't dismiss the compensator coming loose again either, it should be checked.

[MegaGlide]

Crap comes loose during dyno floggings.
Poke, prod and try to twist stuff to see if everything is still tight.
The chrome cap on the end of my starter was loose as a goose after my tune...