Less than a week ago, I think I filled up with some bad gas. I've since been trying to burn it out of the bike with the help of new, good gas, and some STP carb cleaner. Now, I'm hearing a clapping noise coming from my exhaust pipe. I'm not sure if it's related to the gas problem, but it seems to only happen when I'm engine braking in third gear, or blipping the throttle to upshift. As best as I can relate it, I'd say it sounds like intake or exhaust valves clapping shut, even though you shouldn't be able to hear that. The sound is pretty inconsistent and inoften, but it's getting on my nerves.

What could it be?

Other things I've done recently: oil change, lubed the chain, and painted a high-heat black coating over the exhaust pipe.

 

I'm not too sure......one of guys here might have some ideas though - be patient, one will respond.

By the way, welcome to the forums!

What year is your bike? What sort of mileage is on it?

 

Could be unburned fuel passing through and igniting in the muffler (backfire)...Getting all of that bad gas out may stop the noise. But its kind of hard to tell without being able to hear the bike. Good luck!

 

I have a 1995 EX500. It's my first bike. It had about 10,500 miles on it when I bought it in March, and has about 17k on it now.

I heard it still more today. It's really obvious when I'm riding close to a wall, or through a tunnel, where the sound echos back to me. It's definitely coming from my muffler, and is seemingly something within the engine.

Again, I only notice it happening when I let off the throttle, as in upshifting or engine braking. If I pull in the clutch, the noise occurs much less, if even at all. If it is happening when I roll ON the throttle, it's not loud enough for me to hear over the sound of the engine.

Almost like the sound of two wooden blocks clapping together, except without a constant rate, and a bit more . . . metallic sounding?

Any ideas are appreciated.

 

when you painted the mufflers, did you remove them? sounds kinda like an exhaust leak, check and make sure your mufflers are on the header pipe all the way. How much gas do you have left before all the bad gas is out?

 

What engine mods do you have i.e. exhaust, full or slip on, jetting or air filter and air box mods?

JMO but I hardly ever engine brake. There is really no reason and it adds wear and tear to the engine.
New engine 2000.00 new brake pads 50.00.

 

I didn't remove the exhaust system when I painted it. I only went over it with a brush. I've done this once before, and experienced no problems. I'm not sure how tight the muffler is supposed to hold onto the exhuast pipe, but it feels solid enough. And it's not the gas. I emptied my tank and put new gas in there, and I'm still hearing the noise, now seemingly more than before. And now, not only do I hear it coming from the muffler, but from the engine area, too. Specifically, the left side.

The bike has been modded to a single left-side exhuast, fitted with a Jardine pipe. It's kinda scratched up from a drop I had a while back, long before this unknown noise began. There was also an air box mod, but in what way, I don't know. All I know is that the original airbox is in my kitchen, and the bike is fitted with two K&N filters that I cleaned not too long ago.

I rely on my brakes entirely now so that I don't have to hear the noise, but even then, I still occasionally hear it when I'm letting out the clutch while upshifting. I don't think I'll be riding anymore until I've solved this problem.


It sounds like a clanky rattle; an infrequent, inconsistent, and crisp sound. It doesn't seem to disrupt engine performance, though. And, it only happens when the bike is engine braking, whether that be in coming to a stop, or for a single moment when I'm upshifting. If I fully pull in the clutch, it stops. If I'm steady on the throttle, it doesn't seem to happen. And if it's happening while I'm accelerating, I'm not hearing it. I don't know what it is.

 

I had a friend look at my bike today. My chain had a lot of slack. I didn't realize that. Now it's fixed, and no more clanky clanky.

CHAIN SLAP

 

Glad you figured it out! Go figure that it would be something that simple........