Just replaced exhaust donuts and thats not the problem...help

[Z06 FAN]

I was out on the weekend and developed a air sounding noise that I thought was the exhaust donuts. My son posted on a different forum about this issue and got the same response from a Yamaha Tech...exhaust donuts. So I replaced them as they probably needed changed out anyhow. Sled is 2006 apex purchased a year ago with 1,700 kms and now has 3,800 kms on it, so they were gonna be replaced at the end of season anyhow. So I started it up and still have the air type sound...head gasket??? or something else...hopefully simpler lol. We were driving our machines pretty hard when this developed.

 

[TBay Sledhead]

Did you check the exhaust pipe where it goes from two into one. The 06/7 were known to crack or break in that area. I believe in 08 the added a tunnel brace to rectify the problem.

 

[Z06 FAN]

Sound is coming from engine area...engine just sounds louder, noisier. Possibly not air sounding so much now that I went back out to the garage for another listen. Just sounds not right and a little louder. I'm stumped

 

[Viper_Dave]

I've replace my flex pipes twice on my 06. Changed donuts the first time, didn't fix it. Got a good flashlight and started flexing the joints and found 2 cracked . Less than 5,000 miles on the sled !

 

[steiner]

If you snap the throttle does the sled backfire? A backfire will indicate bad exhaust donuts or a cracked pipe. Been there, done that.
If its a loud air rushing sound it could be from the airbox. Maybe the lid popped open or something like that.

 

[john10toe]

Warm up your engine and hold the palms of your hands over both tail pipes while the engine is idling to block off the exhaust. I wear welding gloves to prevent burning my hands. The engine should stall almost immediately if everything in the exhaust is tight. If the engine continues to run while tail pipes are blocked, then you have an exhaust leak somewhere. Nice if you have a second person to listen and watch for leaks at flex pipes, y pipes etc.

 

[CaptCaper]

I bet it's the flex pipes as well. Mine had a crack that was hard to see...

 

[stevieu1]

just did mine... 390 bucks for all four. Hopeful they last another 10000mi.

Sent from my SGH-M919 using Tapatalk

Also had to weld a new flange on the silencer. Nice and tight now!

 

[Z06 FAN]

Just don't sound smooth now so I replaced the plugs...no dice. Gonna check coil packs tonight. Not so much of a air sound now that all body panels are off and I changed the donuts. I did see a little wetness in one cylinder when I removed the flex pipes.

 

[slimjim2525]

Replace your flex pipes, that's your problem, almost guaranteed. Why would you change the plugs if the sled is loud, i'm not following that at all.

 

[budman 1000]

I was out on the weekend and developed a air sounding noise that I thought was the exhaust donuts. My son posted on a different forum about this issue and got the same response from a Yamaha Tech...exhaust donuts. So I replaced them as they probably needed changed out anyhow. Sled is 2006 apex purchased a year ago with 1,700 kms and now has 3,800 kms on it, so they were gonna be replaced at the end of season anyhow. So I started it up and still have the air type sound...head gasket??? or something else...hopefully simpler lol. We were driving our machines pretty hard when this developed.

If your mileage is correct it's highly unlikely you have an exhaust leak unless you have damage from to your exhaust system as in broken support bracket or damage from picks. If you had your air box off and didn't get your hoses all hooked proper like especially the small hose to your engine valve cover it makes a air leak sound from your engine, just a thought as I've seen guys miss that hose and had same as your describing.

 

[FlyinA]

Intake air leak or air box hose disconnected could cause noise and unsmooth running. I'm +1 on carefully checking all the air box connections, including pulling off the air box to check all the intake boots for cracks or poor seal to the throttle body. Re-install the air box carefully, it takes patience to get it on right.

 

[Z06 FAN]

Now I'm at the point where I feel the engine is labouring.Put new plugs in, checked all the coils, checked for codes, TPS is fine. I'm lost!! no air sound any longer...just a rough sounding engine.

 

[FlyinA]

Any idea what got rid of the air sound?

Backtrack one item at a time to find out where roughness came in - bad/damaged plug, loose plug wire, knocked a coil wire loose by mistake, etc.

 

[steiner]

Now I'm at the point where I feel the engine is labouring.Put new plugs in, checked all the coils, checked for codes, TPS is fine. I'm lost!! no air sound any longer...just a rough sounding engine.

Post a vid of the sled running.