Exhaust for 79 KZ1000 LTD

I'm going to be restoring a 1979 KZ1000 LTD, which has what appears to be a pretty decent stock exhaust, but I want to make a little noise with it. I would love to find a Kerker, but they appear to be super pricey. I've been considering the Delkevic system, but hoping for some feedback on performance and sound with that system. I have the Delkevic mufflers on my 1990 CBR1000F, and have been impressed with their quality and sound, but wanted to see if anyone has any experience with the full system for the KZ1000.

Let me know and thanks!

Warner

I have the Delkevic on mine. It turned my closet screamer into a caged animal overnight. lol

It has a deep wicked mean sound that only gets amplified when I crank that go fast handle on the right. It also has a wicked whap whap cackle sound when I let off the juice. It is all part of my 100 HP PTSD therapy. I forget all about all dat BS when I start that bike.

It does turn yellow within minutes of run time, and no matter what they say, it does need to have the A/F ratio fattened up due to the better breathing.

A definite A+ IMHO.

old_kaw wrote: I have the Delkevic on mine. It turned my closet screamer into a caged animal overnight. lol

It has a deep wicked mean sound that only gets amplified when I crank that go fast handle on the right. It also has a wicked whap whap cackle sound when I let off the juice. It is all part of my 100 HP PTSD therapy. I forget all about all dat BS when I start that bike.

It does turn yellow within minutes of run time, and no matter what they say, it does need to have the A/F ratio fattened up due to the better breathing.

A definite A+ IMHO.

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Thanks. You have the megaphone exhaust, right? Did you choose that over the straight pipe offering?

Warner

You indicated your restoring the KZ then say you are not going to use the stock exhaust. Hate to break it to you but you are no linger restoring it once you start putting on aftermarket parts, thats modifying it. Restoration is putting it back together exactly like it left the Kawasaki factory.

"Thanks. You have the megaphone exhaust, right? Did you choose that over the straight pipe offering?

Warner"

I bought it off of a for sale ad on KzR brand new in box. A member had bought for a project, then he ended up selling off his parts. I don't know what happened to his build, but I remember he had some really nice stuff for sale. This is/ was NOS still in the box with bubble wrap still on everything. I didn't know that they offered a straight pipe for it, but it does stand to reason that they would.


I rode this bike for years after I rescued it with the stock system. it always has run absolutely awesome, quiet, but awesome. I had wanted to ratchet things up a tad with my docile old kaw, and this header was a really abrupt change to my mostly stock bike. Especially after that last 100 + speeding ticket with the stock exhaust, I figured I wasn't off the radar any longer so.. wtf. :evil:

I did have to modify the center-stand stop, but not a big deal.

As you can see it's running a little lean. i increased the main jet from #122.5 to #125's a few weeks ago, and it's still a little lean as you can tell.

Your old mains were probably fine. They were themselves oversized. But your pilots are probably a bit small..or you need to adjust your fuel air screws.

Edited to add the following...

Main jets provide the greater amount of fuel from about three quarters to full throttle. From about one quarter to three quarters it is the jet needle that controls the amount of fuel. (The area between the jet needle and the needle jet is less than the area of the main jet until about three quarters throttle so this is the fuel control over that throttle range.) If you are running lean you can lift your jet needles a notch or two and provide a richer mixture in the one quarter to one half range. Up to one quarter throttle the main fuel controls are the pilot system and the throttle valve (slide) cutaway.

If your carbs are original to your bike they are likely VM28SS with an accelerator pump. (I have the same carbs on my '80 LTD) They should have a fuel air screw on the intake side of each carb. This controls the fuel air mixture for the pilot circuit and should be properly set in order to provide a rich enough mixture to avoid pipe bluing. I don't have my manuals with me so I can't give you the correct range with certainty but I believe it's about 1 and 1/8 to 1 and 3/8 turns out from lightly closed. I would start with the setting in that range and tighten them up a bit (maybe a quarter turn) if the mixture is still too lean.

If your carbs are original to the bike I would not worry about the cutaway. It should be fine. But if you are running early Z1/Z1A carbs they have a greater cutaway and would run a bit leaner in the lower rpm range.

"Your old mains were probably fine. They were themselves oversized. But your pilots are probably a bit small..or you need to adjust your fuel air screws."

You are probably right. The mains have the most effect at the larger throttle opening. In thinking about it, although I may be running sustained high revs / speeds, the throttle is still only around or under half cranked.



The carbs on my bike are Mikuni BS34, per the manual. They don't have all of those fancy adjustment screws or a accelerator pump. lol It has the stock 37.5 pilot jets, so I assume if I order in some #40 pilots it will fatten up the range the bike spends most of it's time at while administering my therapy. :woohoo:



edit: My needles don't have all of those fancy notches either.. For me to raise the needle, I either need to replace them, or shim them up with a washer. I did have a #4 washer under all of them, but it did not seem to help, so I removed them when I replaced the main jets.



I found this page on Mikuni tuning. Just FYI here.. It says if the pilot screw is located at the front of the carb, it regulates fuel, and if located towards the rear of the carb, it regulates air.

www.iwt.com.au/mikunicarb.htm

I totally agree old_kaw, although I've never worked on carbs as new as yours. I see on your chart there is no curve for the slide cutaway. The old Kaw training manuals (not the service manuals) had a really good set of curves for Z1/H1/H2 carbs, including the slide cutaway.

I think '79 was the first year for the accelerator pump on all KZ1000's. The story I heard was that over the '70's KHI went leaner and leaner to comply with emission regs and the bikes began to bog off the line so they added the pump to give a little shot as the throttle was cracked. The carbs that year and in 1980 have a fuel/air screw on the back, not the fuel screw underneath on the front.