1980 KZ440 LTD Mac 2 into 2 Advice

If this is in the wrong category, I apologize. I'm in the midst of slowly restoring my 1980 KZ440 LTD D (belt model) and I've been thinking of getting the aftermarket 2 into 2 MAC exhaust system. Has anybody in particular done this on a 440 and if so, do you have any advice?

My exhaust pipes aren't in the worst shape ever, but the right muffler is completely rotted through on the exit hole and it's beginning to rust through on the insides by the frame. It takes away from the bikes aesthetic considerably, and is super loud on the highway so I want to get this done. My only problem is that I shudder at the though of rejetting. Right now, the bike runs like a dream. The throttle response is like butter and the idle is absolutely perfect. It's very well behaved, but that didn't happen overnight and the thought of stabbing in the dark to try and get that back by rejetting keeps me at bay.

So again, if anybody has any advice or knowledge to either, A) make this an easier decision for me B ) Reassure me that rejetting won't be necessary C) Offer your personal experience with this or D) All the above , I would be grateful. Thanks!

There's a NOS OEM 440 muffler system on EB right now. Not sure how the cost compares to a new Mac system. even if it's more, it should be less trouble.

1980 KZ440 mufflers. From Canada. approx. $330T.
K2300 PAIR of MUFFLER for KAWASAKI KZ440, 1980

No eBay APP ID and/or Cert ID defined in Kunena configuration

martin_csr wrote: There's a NOS OEM 440 muffler system on EB right now. Not sure how the cost compares to a new Mac system. even if it's more, it should be less trouble.

..... 1980 KZ440 mufflers. From Canada. approx. $330T.

Hey, that's not such a bad idea and thanks for the link! At least with these I wouldn't need to rejet (hopefully)! They're cheaper than the MAC system too, even when you add on the $70 dollar shipping.

I did not do an exhaustive search (pardon the pun), so I don't know what else is available & I don't know if that cost is reasonable for a 440. Just guessing, I'd say yes.

Having had to replace my two into one and re-jet my 440 to bring to stock ; I have replaced my pipes twice. Hard to find a good right side pipe. Those pipes are awesome and I would definitely jump on those.

Grcko wrote: Having had to replace my two into one and re-jet my 440 to bring to stock ; I have replaced my pipes twice. Hard to find a good right side pipe. Those pipes are awesome and I would definitely jump on those.

Yes, I think this is the route I'm going to take. I wasn't really planning on spending $320 dollars today, but I've not come across such a clean OEM pair before. Speaking of the right hand pipe, why exactly does it have all those circles in it? I'm pretty mechanically inclined but I don't know enough about exhaust systems to understand their significance.

I must have lost my mind, but I just bought the OEM pipes. I know that I will regret it if I walk on these, and then a year from now they totally rotted through and I'm in for a massive headache because I didn't take advantage of the cleanest original OEM pipes I'd ever saw.

Looks like my 1980 KZ440, whom I call Eleanor, will be getting yet another face lift here soon. I just dropped over $300 on getting her tires and having them installed. While the tires were off, I went and worked through the entire bike and cleaned her up. I think I'll start a project thread soon and share the journey/progress I've made so far. She's getting closer and closer to showroom quality!

A special big Thank You to martin_csr for finding those pipes for me, by the way! I you just made a huge impact on my day and on my bike, and I'm very appreciative for the help!

The price does't seem that bad to me for NOS & OEM.
To deter rust you could treat them with an exhaust coating >> I used Rustoleum silver bar-b-que grill paint on a very nice used KZ750E system. see pics. In addition to the manifold section chrome, I cleaned & sprayed the insides. I did not sand the chrome or anything. kinda surprised the paint hasn't peeled off.

martin_csr wrote: The price does't seem that bad to me for NOS & OEM.
To deter rust you could treat them with an exhaust coating >> I used Rustoleum silver bar-b-que grill paint on a very nice used KZ750E system. see pics. In addition to the manifold section, I cleaned & sprayed the insides. I did not sand the chrome or anything. kinda surprised the paint hasn't peeled off the chrome.

He'll be able to use that to preserve the original crossover pipe.

The spray paint coated the crossover section pretty good, inside & out. But for the insides next time, I'll probably use a high heat paint that comes in a can & just pour it in. The rustoleum worked, but using a funnel will be easier than trying to spray it inside the pipes. I would still use the spray paint on the hidden areas of chrome.

If you are worried about long-term condition of the pipes, then OEM is the way to go. A set of good condition ones will outlast Mac stuff by a long shot. The Mac exhaust I bought started to show signs of rust by the end of one season. They are ok pipes but you really only get what you pay for. The OEM stuff is way stronger and will last longer... the only downside with them is that they are heavier...which is probably why they last longer in the first place.

The original factory exhaust system on my 1977 KZ650 is still in great condition, and I suspect one reason is the fact that it is double walled. That is to say there is a second set of pipes inside the outer pipes that one sees when looking at the exhaust. This prevents the pipes one sees from turning blue unless there is significant over heating. I could be wrong, but I would expect the original pipes on the KZ400 to be made in the same fashion. Consequently, they should last pretty much forever although there is a weight penalty for such a robust exhaust system. The image below shows one end of one of the stock header pipes. I don't know of any aftermarket exhaust system made with double walled pipes. Ed