Mac Exhaust Rattle and Colour Change

Hi Folks,

I've recently purchased a mac exhaust for my KZ 650C1. Its the black pipes with chrome muffler version.
I'm quite disappointed with the product.

First, although I've noticeably gained low end power (probably because the old pipe had holes at the junction), seems the top end power is falling off earlier (around 6.5K rpm).

Second, there is a rattling sound (not huge but noticeable) coming from the inside of the muffler. I checked to see if pipe was banging anywhere on the engine or frame but it doesn't seem to be the case. Between 4.5K and 6K rpm it rattles due to vibrations.

Third, the exhaust headers have turned brown after riding just a few hours. I've never heard of this before and its pretty damn ugly. I know that chrome pipes will turn blue when the mix is a little hot and rich, but black pipes turning brown?!!

Do you guys have any experience with this. Any recommendations to resolve the sound and colour change?

I'm bitting my tongue but wish I had spent the extra $200 for a Kerker...

Cheers,

did you re jet the carburetors or just throw the pipe on? :blink: the noise is more than likely coming from the baffle.
get yourself a can of stove black to touch up your headers, rub it on any bare spots.... probably a lean condition is causing your paint to come off or cheap paint......... :huh:

Thanks Turboking!

I just threw the pipe on. The previous pipe was also a 4 into 1 so I assume the previous owner worried about the jetting.. but that could be part of the power problem.

Yes, I guess I'll have to touch up the headers with some flame proof paint. I don't think the paint is coming off, but instead just turning brown. I'm going to check the plugs and play with the mixture screws on the carbs over the next couple weeks.

The MAC on my 750 twin jets out just about same as the stock pipes. And if it's any consolation: if you had gotten a chrome pipe, the headers at the turn would be a deep royal blue by now..... even if jetted correctly.

Thanks bounty,

I think blue would have been better... But anyhow can't have it all.
Maybe I'll get the kerker some day...

Cheers