Yoshi Exhaust Problem

[Mikeee P]

I've got an odd one. A 2006 Busa, with a nice decent stock exhaust sound. Installed a Yoshi full system last night and now, it almost sounds like there is something loose in the exhaust. On decell when I rev it up and let it idle back down, it's making a clicking or snapping sound. Hard to explain the exact noise.

I used all new exhaust gaskets, they're installed correctly as well... as mentioned the motor/engine sounded perfect with stock exhaust - but the moment I cranked this I was like "Whoa...". I've tried it with and without the diffuser baffle and it changes the tone of the noise of course, but it's not a loose baffle or anything of that nature.

Any clue what might be causing this? We're talking about something with no moving parts now making an annoying tick/ding/click/ LOL

It does it slightly while idling - but it's most noticable on decell after you rev it up and the revs start to drop back down.

Help a brother out - have to have this issue fixed today/tomorrow at the latest!

Mike

 

[Mr Bogus]

The slip pipe fit can do this... my TiForce has a little bit of that racket when cold but as the pipes heat up, they tighten up.

Did you try riding it a bit? perhaps yours will quiet down when it warms up?

 

[craigntx]

when some loose concrete flew up and made holes in my yoshi it made that ticking noise
i thought it was the motor

 

[roadthing]

Check your springs(if any), and clamps.

Also, it's always a good idea to use high-temp exhaust flange RTV on your slip-fit exhaust sections, before clamping them. It will help seal the sections, it will also make future disassembly easier (stops corrosion between sections), and will help eliminate any noises associated with a loose fitting section.

 

[Mr Bogus]

the slip fittings tighten up with heat on their own.. inside pipe is always the upstream pipe with the most heat..
As the pipe heats it will grow and tighten up..


Not sure that it does any harm to put silicone in the gap but certainly not necessary..


I know that some moisture escapes from the gaps in my pipes when warming up.. titanium or good stainless should show minimal if any corrosion issues..

 

[roadthing]

"Not sure that it does any harm to put silicone in the gap but certainly not necessary..


I know that some moisture escapes from the gaps in my pipes when warming up.. titanium or good stainless should show minimal if any corrosion issues.."

I respect your opinion, but I disagree with a couple of items.

It does not do any harm to use a high-temp exhaust flange RTV (it will be O2 sensor safe) at the exhaust joints. Several manufacturers recommend it (BUB, Supertrapp, and BMW OEM) and it beats the snot out of using graphite tape at the joints.  If you use a torque wrench, and some exhaust flange RTV, you will be helping your exhaust system up for a long, and trouble free service life.

Titanium and stainless are not corrosion resistant. I have seen stainless exhaust systems actually crack. These faults were from a few different causes, including production flaws. Aerospace grade materials will show the least amount of impurities that can lead to both galvanic, and "least noble metal" (cathodic) corrosion. The stuff that is used in our exhaust systems is good quality, but not the greatest. Any corrosion that is left unchecked will only get worse over time. An ounce of prevention is worth a pound of cure.

One other thing to check would be the welds throughout the system. A small fracture at a weld will sometimes produce noises at different times, under different conditions (heat, vibration, etc.). Sometimes welds are faulty right out of the box, and sometimes due to a misjudgment in installation. I have also encountered a bunch of systems that had welds that fell victim to hydrogen embrittlement, and failed within weeks of being installed. That was a fun two months!

I don't know if that's going to address the noise problem as described, but it can't hurt.

 

[RedBull]

Mikeee P

www.hayabusa.org