1980 KZ440 LTD Mac 2 into 2 Advice

Yeah, I certainly will take measures to protect it. I don't want to have to get on my hands and knees after every ride and clean the pipes thoroughly just to ensure they don't rust out. However, I take really good care of my things for the most part , so if I had to every time, I would. lol

That's good to know, thank you. It doesn't bother me that they're heavier, especially if that means more durability. My aim with my bike is to restore her to original showroom quality but with a little character.

Well, the pipes that I bought arrived today. I was super excited to install them, but I noticed something was off immediately after taking them out of the box.... These are not the same pipes! Each muffler is meant for a different sized crossover pipe and I am stunned. The post said a pair of mufflers not two mufflers, each from a different sets. I've attached some images for comparison. Am I mistaken here or is there some way I can make them fit without negatively affecting the bike's performance? I'm at a complete loss here, and any help is very much appreciated.

On a side note, bikebandit shows two sets of mufflers under OEM Mufflers. One is for the '80 D1 and the other is for the '81-'83 D2,D3,D4, D5. These are all belt driven models and the each pipe no matter which you click on shows that it is compatible with my 1980 KZ440 D1! However, the schematics are different. This is the schematic for the '80 D1 Mufflers. Notices that the crossover connectors look exactly the same and how part '7' looks. Now This is the schematic for the '81 to '83 D1-5 Mufflers. The part numbers are different but it looks exactly the same except that There is an image shown of a smaller crossover pipe, all on its lonesome, marked part number 32032A. This part seems to be what would fit the muffler with the smaller crossover connector. Is it contained inside of the larger one, or what the hell is going on here? Because once again, each of the two crossover pipes shown also say that they fit with my bike! I'm so confused.

My pipes as shown below the bike where they connect


The new pipes showing where the crossover pipe would be.


The left hand pipe


The right hand pipe

Also, I forgot to mention that the back sides of the pipes are reversed as well. The one with the flat surface on the mufflers end is on the right and the 'circle indented' one is on the right, for the new pipes. It is reversed for my current pipes. I'm not sure if this is relevant or not. This is also contrary to what the bikebandit's schematics show, as the Right Hand Side pipe is listed as the 18001A/D part number, but the new pipes have the left one labeled as the 18001A/D part.

Both are marked for the 440, so that's a good sign. Assuming the system fits otherwise, a couple of solutions for the crossover: maybe you could come up with a simple adapter >> possibly from copper pipe fittings. and to make up the difference on the larger connection, maybe install a muffler gasket if you can't find anything to fit right. PartsNMore has the gaskets. I have them if you need measurements.

Edit: the 81-83 diagram drawing doesn't show it, but there are possibly 3 different styles of mufflers as there are 3 different part numbers for the LH & RH mufflers >> the mufflers that would fit the 32032A crossover aren't shown, but they are listed in the diagrams at Partzilla.

Do you think that the difference in size for the crossover pipe would cause any kind of negative performance issues? Also, I'm unsure exactly how I would reduce the diameter of only one side of a custom copper pipe in order to make them fit together in the center, or exactly how this would work overall. Unfortunately, I am completely experienced with exhaust system work.

I doubt the difference in diameter matters. Measure the O.D. of the smaller one & the I.D. of the other. then head over to the hardware store or website to see what they have. I'm thinking you'll need a short section of copper pipe plus one or two fittings. perhaps just a section of pipe, a coupling plus 1 crossover gasket. ...LH muffler >> copper coupling + copper pipe + copper coupling >> RH muffler

For the gasketing you could probably use something from the auto parts store, maybe some exhaust tape plus some high temp rtv to seal everything. Someone here on KZR used copper fittings to repair his 650-CSR mufflers which had rusted out at the crossover.

Edit: you could complain to the seller that the muffler system is mismatched to see if he'll give a partial refund to offset the nuisance & extra cost. Twenty bucks is twenty bucks. or however much you can talk him into. I wouldn't hold my breath, though.

It looks like the O.D. of the smaller one is 30mm. As for the big one, it's a bit wonky. I realized the big one is not a perfect circle and is bent downward slightly. At once cross-section the I.D. is 36mm, but measured from the wonky end it is 38mm. I've been searching for exhaust reducers/pipe reducers which can be clamped (I have zero welding experience) that could accommodate a 36-38mm to 30mm reduction, but haven't found any yet.

As for reaching out to the seller, this is what's playing on my mind the most. It was marked that he wouldn't accept refunds, but at the same time it was listed as a muffler set for a 1980 KZ440, not a muffler from a '80 KZ440 and a muffler from an '81-'83 KZ440. If he wouldn't play ball, I'm sure eBay customer service could assist but I could be stuck with shipping charges again. Plus, these pipes are hard to find but unfortunately I really not a big fan of jerry-rigged solutions. I'm really torn into two as to what I should do.

Like Martin said, it shouldn't be too hard to get a pipe and reducer as needed. This should be able to be done without welding, I would think...just clamps.

I also agree that the small difference in the crossover pipe diameter won't affect performance much at all. Heck, it would probably even work fine if you just capped each end of where the crossover pipe would attach and didn't even use a crossover pipe.

I would try to mark the item "not as described" and instead of a refund, ask if the seller will refund you a small portion of what you paid. Either way, worst case scenario is that you get stuck with the pipes, and they will probably work fine.

1-1/4 copper pipe should fit over the 30mm LH muffler pipe (1.25" = 31.75 mm). some hardware stores sell short sections for the do-it-yourselfer. If the fit is loose, you could then cut 2 to 4 slits into the end of the copper pipe & use a clamp.

An 1-1/4 copper fitting might fit inside the RH muffler pipe >> possibly a copper coupling or male or female. or 1-1/2 x 1-1/4 copper reducer.
Also, you might be able to use the old crossover pipe somehow. either entirely or cut a section from it to act as a reducer.

I would go to the hardware store & see what will work. You could bring the old crossover pipe to figure out the RH muffler. Or fashion a couple of tubes to act as templates for quickly comparing what will fit what, instead of trying to measure everything.

If there is a muffler shop open nearby, I bet a guy there could whip up a suitable pipe in short order.

Yeah, I decided that I'm going to keep the pipes. I have never come across a set that was so near pristine as these are. I just felt overwhelmed at first because I was not expecting this and because I have no exhaust work experience at all. However, I'm feeling better about the whole situation as of this morning and I'll do whatever it takes to make it work. It was a steal of deal, honestly.