Kz 440 MAC Exhaust Questions

Hello everyone. It has been a long winter but I finnaly got the bug yesterday ant took my 440 out for a spin. I don't think I have ever been on a bike before the first of April. Living in ND I can't complain although it was only 29º F.

Anyway I found a 2 into-2 MAC exhaust for my 83 440 and was wondering if people have had to re-jet the carbs when running this exhaust kit? I have the factory air filter and air box installed.

Tyler wrote:

Hello everyone. It has been a long winter but I finnaly got the bug yesterday ant took my 440 out for a spin. I don't think I have ever been on a bike before the first of April. Living in ND I can't complain although it was only 29º F.

Anyway I found a 2 into-2 MAC exhaust for my 83 440 and was wondering if people have had to re-jet the carbs when running this exhaust kit? I have the factory air filter and air box installed.

I put a 2-1 MAC on my 750 twin and I did have to rejet and change the needle positions. Mine runs OK with the stock main jet but I had to go about three sizes richer on the pilot jet and two slots richer on the needles.

Ok so I will probably have to do some tuning. Is there a good place to find jets? Are they a statndard aftermarket type, or do I have find used and NOS OEM parts?

Tyler wrote:

Ok so I will probably have to do some tuning. Is there a good place to find jets? Are they a statndard aftermarket type, or do I have find used and NOS OEM parts?

This place had the biggest selection and lowest prices on jets for mine:

www.psep.biz/

They were the only place I found that sold jets in pairs isntead of making you pay twice as much for a set of four.

All the other places don't seem to realize that not every bike on earth has four carburetors....

You should run it first, yours may run OK with the stock jets. If not, you can tune it up.

Thanks for the link. I'll have to see how the bike runs when I get the exhaust on it. I don't expect much of a change but its nice to kow I can get different jets easily enough.

I find that these smaller displacement Kaws can get realy finniky when you start changing intake and exhaust components.

Wow someone else from ND. Ya I know its till a tid bit nipply up here but since there isn't much snow a few friends and I have successfully rode in every month of the year. About the exhaust though I just put a Macs 2-1 on my KZ750 twin and I didn't have to rejet just move the clip on the needle down one. I think it was running pretty lean to begin with though. From what I'm told the mac's really don't flow that much better then stock and I gotta say it isn't the best quality I've ever seen, but my stockers were shot and I needed new ones and the macs were very easy to install.

I keep hearing about a removable baffle in this exhaust. IS there any effect other than noise to removing the exhaust baffel?

Tyler wrote:

I keep hearing about a removable baffle in this exhaust. IS there any effect other than noise to removing the exhaust baffel?

It will probably increase flow and make the engine run leaner. It will not necessarily improve performance.

You can also call up z1enterprizes for your jets. The cv36 carbs that are on the 440 have a slow air jet as one of the main jets... Anyway the z1 guys will know what you need...

I installed the exhaust yesterday. I would agree that the MAC kit isn't the best of quality. The pipes themselves are very nice and the chrome looks to be done right. The mounting hardware is pretty crude though, and there is the complete lack of any instructions. However the kit did fit pretty well, and it's not too hard to figure out, but you will have to "tweak" a few of the mounting brackets.

The bike runs great, I may not have to do anything to the carbs. I am gonna have to drive it for a while and see. I did suspect it was a littel on the rich side before I started, but it ran about the same with the new pipes on. The sound on the other hand is pretty cool. My 440 sounds pretty mean, I would think the biger bikes would sound much nicer though. :evil:

I had been watching these kits for a while, and I bought the last one Dennis Kirk had in stock because they knocked the price down $50. It's the only option you have if your cleaning up one of these old twins other than buying used stuff.

And thanks for the quick answers guys.