Testarossa's 78 KZ1000 Fighter Build

Here's a look at the perforated tube that I stole from a guy named Leo Vince:

After all that fun, I popped the tailpipe back on the bike, and installed the oxygen sensor. Fired the bike up after calibrating the sensor, and what do you know, I at least got the screws adjusted right. It was hovering between 14:1 and 14.7:1. Now when I took the bike around the block, the effects of my new baffle came to light. With the original, more restrictive baffle, it seemed to be jetted fairly well. Now it has a big stumble off idle that it can't get past even if I twist it to 1/2 throttle. This registered as a/f ratios between 17:1 all the way to 20:1 :ohmy: Time to bump those pilot jets back up, and I'm guessing that the needles may need adjusting as well. If I pulled the choke out about 2/3, it got the a/f ratio down to about 15:1, and the bike pulled much better. I would still like to see an a/f ratio more in the neighborhood of 12.5 to 13.0:1 under a load.

So, I'll go back to one adjustment at a time. I was also able to get a brief log of of the a/f ratio in the garage. I'm pleased to report that my wal-mart sd memory card works, and so does the LogWorks software included in my kit. I'm looking forward to getting my connector in the mail, so I can hook up my other sensors. I'll have a/f ratio, rpm, manifold pressure, and throttle position all continuously logged. This will help to determine where the a/f ratio is at all times. Just logging the a/f ratio by its self doesn't give you a frame of reference.

Fantastic! It's great when a plan comes together You'll get your jetting nailed quick and perfect. Wideband is the only way to fly.

One question about your muffler Josh, though it might be to late for you to accurately answer:

What is the perforation size and spacing on the exhaust core? I was going to have one of my sheets of Ti laser perforated with 1/16" holes on 1/8" centers on an offset. It looks like the core you used is the same configuration, but if it's not, I'd like to know if possible. Thanks

Adam, it's not too late. I still have the other half of that tube that will make up my shorty muffler for the ninja. It hasn't been buttoned up yet. I know that they are bigger than 1/16". Since the pipe is italian, I'll guess that they are 3mm on 6mm centers. I'll be able to measure that when I get home this evening.

nice work man!
that straight through baffle looks close to the one that i have in my z1r.just perf tube with an end cap.gets me passed the leo's and seems to run well enough for me.i have a smaller diameter baffle of the same design and it really restricts it.
i dont have no afr #'s or anything but .

leon

531blackbanshee wrote:

nice work man!
that straight through baffle looks close to the one that i have in my z1r.just perf tube with an end cap.gets me passed the leo's and seems to run well enough for me.i have a smaller diameter baffle of the same design and it really restricts it.
i dont have no afr #'s or anything but .

leon

What diameter is that perforated tube in your baffle?

i will have to measure it.hopefully i make it out to the shop tonight.
i just recieved a new adjustable boring head and have a ktm upper triple to open the steering stem hole up some.
so i plan to be out in the shop .


leon

Adam, the holes in question are 3mm (0.118") diameter on 5mm (0.196") centers, and staggered.

Thanks Josh! That perforation is larger and the spacing closer than comonly available automotive muffler cores. I too am curious about Leons muffler core specs.

One other thing that you may find interesting is that the perforated tube has a slight taper to it. The original, full length tube was about 2 1/16" ID on the inlet side, and 1 15/16" ID on the outlet side.

That is interesting! It's fitting that I was just contemplating making a reduced taper core, and I was wondering what kind of effect that would have on noise and performance. Yet, here it is in a performance muffler. How is the external input sensor wiring coming along?