kz400 exhaust

first post here, with an interesting question and a little backround.

i've got a 79 kz400 that i was going to sell recently but the deal fell through ( with no hard feelings! ) and i decided to get the bike running. finally after two years of fighting got the paperwork to get the title ( fingers crossed! )

anyhow, long story short she lives, runs fine, but has alot of vibration just above idle. i looked at the exhaust and the left pipe is cracked between the muffler and pipe, almost to the point of falling off.. i am guessing that is at least part of the problem with the vibration. now, i can just weld up the crack, and i'm sure that life would be fine, however, i thought about turning it into a 2 into 1.

my question is 3 fold..

1. anyone here try a home made 2 into 1? i've gotten a good look at a few different systems and it looks pretty straight foreward.. but what are the hidden issues i have yet to encounter?

2. preformance is not the goal, i just think it'd look cool with a 2 into 1 and possibly a different muffler: do you think i'll be looking at a rejet?

3. i know i'll have to fabricate up a new mount for the exhaust, however, do you think on the left or right would be ideal?

i guess some random last thoughts on it are heat issues, and opinions there, as well as possibilities for an aftermarket megaphone, or think i could just use the stock?

thanks in advance, jared.

I guess if you have a mandrel bending machine and are skilled at pipe fabrication and welding, you could make one. I still think you would need to buy some kind of aftermarket canister.

I'm old and lazy and I can't imagine the major PITA all that would end up being could justify it since you can probably find a used exhaust for $100 or less if you really look. The MAC systems are not great performance but they do work.

well, i do have access to a bender for exhaust and while i don't have a HUGE amount of experence, i have repaired a few exhaust systems with TiG welding, and fabricated one up for a go cart from existing motorcycle exhaust. i have no problem with finding an aftermarket canister, i had just hoped to keep the megaphone look. i may just repair what i have, as well, just exploring options.

:edit to clarify my intention:

i'm looking to fab it up from my exsisting cracked exhaust, not making a brand new one from new stock tubing. looks like a matter of just sticking a bend into the one pipe with (probably) a little additional tube stock to make "ends meet" so to speak.the y where the pipes meet on every system i have looked at seem to come in at about a 70 degree angle or so i could fab that flange into the other pipe, slot it and spread it do attach and then weld and/or clamp it up. looking at the system it shouldn't affect the oil change or anything.

You only need to rejet when you need to rejet. Once you have the system on you will have to try it and find out.
Most of the pipes that are 2-1 on KZ exit on the right side but maybe it would be cool to have it exit on the left. I know I would start asking questions about the exhaust if I saw it on the left. I'm not really sure why but it seems like every pipe for every bike exits right. Maybe its a law?? Either way I think it would be sweet to make it look like a Kerker or something similar to that. Just my opinion. Post pics!!

PS I forgot to mention. If you have the two pipes coming together you are going to have to use a flange because the pipes hook up to the engine at an angle and if you can't separate them to take the exhaust off then it is really gonna suck to take them off or put them on.

Becker wrote:

Most of the pipes that are 2-1 on KZ exit on the right side but maybe it would be cool to have it exit on the left. I know I would start asking questions about the exhaust if I saw it on the left. I'm not really sure why but it seems like every pipe for every bike exits right. Maybe its a law?? .

I always figured it was to leave access to the sproket/chain (assuming it was on the left side).

Becker wrote:

You only need to rejet when you need to rejet. Once you have the system on you will have to try it and find out.
Most of the pipes that are 2-1 on KZ exit on the right side but maybe it would be cool to have it exit on the left. I know I would start asking questions about the exhaust if I saw it on the left. I'm not really sure why but it seems like every pipe for every bike exits right. Maybe its a law??

It's the law of avoiding the drive chain.

The KZ400 S models had 2-into-1 exhausts. Maybe you can get photos of one from somewhere and see how Kaw did it.

Are you aware of the KZtwin forum?
www.armbell.com/kz400/index.php?sid=c35c...fcc2365&mforum=kz400

I'm sure someone there must have a 2-into-1.

Actually, someone here has a great thread showing the factory 2-into-1:
kzrider.com/index.php?option=com_kunena&...w&id=224101&catid=11

loudhvx wrote:

Actually, someone here has a great thread showing the factory 2-into-1:
kzrider.com/index.php?option=com_kunena&...w&id=224101&catid=11

yep, that looks pretty similar to what i've seen with the aftermarket pics. does not look overly complicated to me.. i think i am going to give it a try!