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Second season on my '78 Kz650B. Got it from an amazing guy in NYC who did a crackerjack restoration. The minute I saw the bike on CL, I knew I would own it someday. Paul did all the right stuff...which included popping a MAC 4-1 on there. It's good. I like it. Sounds good. BUT......... but....but...BUT..

...I WANT A KERKER!

WHY???

Why is that? Is it leftover lust from my '02 ZRX1200 days? Is it the name? The race baffle? The price!?! LOL.

Talk me OUT of buying a Kerker this summer, guys. Are they REALLY $875.00 of awesomeness?!?

Fallback plan is the Delk. It just doesn't turn me on like that Kerker, though....

I was always into drag racing and Rc Eng and Vance and Hines were my hero's ........ so when the V&H header came out it was must have. I drove 40 miles on a Friday in Nov in the worst ice storm to pick it up at a UPS outlet cause they said it would not be delivered till Mon. I had the bike sitting in my third bedroom and I could not WAIT. I still look at the bike every time I go to garage and get a minor chill up my back and smile. Wow after 40 years that alot of smile in.

The Kerker was and still is God's gift..... would have been a super strong second pick ....... even wish I would have picked on up one to keep greased up in the box......... is it worth a thousand bucks with the comp baffle........ that's a tough one but maybe one only you can answer. The way it sounds though every time you ride it or check it out you'll wish that name plate said Kerker instead of Mac.

Ok, I preface this by saying I love the Kerker megaphone exhausts! I wanted one so bad, that I bought a brand new system before I even had a bike to put it on. I found mine on-sale-on-sale during a black Friday event and paid slightly less then than half of the normal $875+ shipping price. It came in a Kerker/supertrapp box, with instructions, additional hardware and a Kerker/Supertrapp catalog. It was not a knockoff!
That said....it was total shit quality, and I do mean shit! The brand new ones are not made to the same quality as the older units we all know and love from 70's to 90's.
I will explain.

1. I ran the exhaust for not even 10 min and the paint/coating totally crazed over and started flaking off. The bike was not running lean and did not "melt" the coating off as I would suspect if I saw this picture. In fact, the worst damage was not on the header pipes at the head (hottest part) but lower down at the collector. The spots areas where the coating completely flaked off, it started rusting immediately. It was so bad, that I had to have the entire factory coating glass beaded off and repainted.

2. The welds. The welds especially the collector are of the very worst quality. You can see voids, spatter and a generally wonky bead. What you don't see in this picture is the inch of MIG wire sticking out from the weld in the confluence of the header pipes. Is that a bad thing, no, but it speaks to the lack of quality control where ever these are made. The voids in the welds are what really concerned me. I eventually cut up the exhaust and added more upsweep and had the pipe professionally re-welded.

3. The baffle after 10min of running (yes, it never got hot enough to fully burn off the moisture.) was utterly and completely encased in rust after sitting for a couple of days. The perforated core baffle came from the factory as bare steel with zero paint or coating. For $875, the baffles should be made out of stainless steel! I guess they do that on purpose so you will pay them $150-200 for a replacement baffle in two years. I also had to glass- bead the baffle and coat it was well.

4.The little things. The exhaust spit-collars all were poorly stamped and came with "spikes" on the flat surface that compresses the header flange into the exhaust copper gasket. I didn't notice these defects at first and when I bolted the exhaust on for the first time, the spikes deformed the sealing flange to the point they wouldn't seat properly. I had bad exhaust leaks until I hammered the sealing flanges on the header flat and removed the spikes from the split-collars.
I had numerous washer provided and most were missing chunks out of them. Does that make them unusable, again no, but it speaks volumes about the quality of materials and a complete lack of quality control by Kerker. Also, the gauge of metal the system is constructed of is thin! Yes, this makes it light, but you can also dent it by staring at it too hard.

If I had paid full price for this system, I would have been livid! For the MSRP, I was expecting to get a quality made product from an American company that has been respected for ages. What I got, was not that. I paid half and I'm still bitter. I still love the way the exhaust looks and sounds and I understand why you want one so bad. Just beware, as that it may not be as well made as they probably once were.

Dang Rusty that sad to hear. I have heard the same with the new V&H headers too.

Delkevic , it won't rust out you can either have megaphone or straight at a smaller cost that will last a lot longer too.

Wow, I'd look for an older system and stay away from recent production.

The new supertrapp KERKERs are definitely not the same as the originals. But they still look and sound awesome.

I got lucky and found a chrome KERKER for a J engine on some company's shelf in Germany. It was the last of the discontinued chrome exhausts.

The chrome blued at the head even though I painted the inside to prevent it. And the baffle loosens up from expansion and contraction. But it still looks and sounds too cool, the welds are high quality, and unlike the originals you can change the oil filter without pulling the exhaust.

Started with the 2" comp baffle, but too loud. The standard 1.5" is perfect for the street.

Added an O2 sensor after the collector for the AF gauge (can't see it unless your on your back looking up). I wouldn't want anything else. Nothing will look this good! Plus the name...

I had a Mac and hated the sound. I kept the header and put a Kerker K2 muffler on it and it sounded great and the engine breathed a lot better too. It only cost about $50 (used) back in the day.

Thanks for the information, good to know stuff here although my dream exhaust to find would be a old Denco pipe. That's the pot-o-gold at the end of the rainbow for me. I had one on my '75 Z1 B back in the day and loved it. I have even gone as far as trying to convince the people making the reproduction Denco 2 stroke exhaust to re-make the 4 stroke system, but they won't do it. They say it would be too expensive.

Rick H.

There are some great hand bent pipes still being made in Japan. japan.webike.net/ps/#!p.m=6284&p.c=1002&p.sk=1

No eBay APP ID and/or Cert ID defined in Kunena configurationif you got the bucks to blow you could do worse than this...

Send it out for ceramic coating when you get it. I had the system on my 750 done and it was quite affordable.

I've ran Kerkers for over 200,000 miles on KZ650s, but back in the day they were $200.00. The main thing they did was sound "better" if you like more noise, a good bit lighter than stock exhaust. Other than that they do no good for anything. Well I guess since stock pipes are mostly non existant, rusted out ect and expensive, the Kerker can replace beat up pipes. Looking back 42yrs, my dad and me went in to buy a brand new 1978 KZ650 that the shop "upgraded" with a Kerker and K&N filters. We bought it and didn't even ask for the original parts, which are 1000x superior in every way. All aftermarket exhaust is crap and only good for a couple pound weight loss and more noise. For $800, they can eat that crap, but I suppose $200 in 1978 is worth $800 now. My inflation calculator doesn't see it worth $800 by about a $700 margin.