Mac exhaust systems

So the hack job exhaust system that came on my XJ650J has got to go for a number of reasons. I was wondering if anyone out there had any experience with the Mac exhaust systems, as they seem to be the only option out there. I prefer the look of the 2-2 taper tips, but I understand that with no collector/crossover pipe, it kinda throws of the original design in the backpressure department. My second choice would be the 4-1 with megaphone muffler. If anyone has any experience with either of these, any thoughts would be appreciated. Installation notes? Re-jetting carbs? Overall satisfaction?

 

My xj750 Seca has a Mac 4 into 2 exhaust ..I like it looks very much stock

 

Thanks Jet! I agree. I much prefer the stock look of the 4-2. Did you have to make any fuel adjustments? or have any fitment issues?

 

Marving makes a 4-2 as well. They aren't distributed as widely in the U.S. though.

 

The po had put it on . I did put in 124 and 41 pilot....it runs great. Stock was 120 main 40 pilot. It ran ok with stock jets though .

 

Thanks K-moe! I looked into it a bit. It appears they make a replacement collector which is kinda cool. I can clean up the headers. I can replace the mufflers. Collector is in really rough shape, and a previous owner welded incorrect mufflers to it which don't mount properly to the frame. Now is as good a time as ever to order from England I suppose.

Thanks Jet. I figured that might be the case.

 

The mac on mine have a good sound and baffles can be removed also.

 

Here's a thread I made on the Mac 4-1 system on my Seca 550, includes a video of the bike with the exhaust
http://www.xjbikes.com/forums/threa...into-1-review-sound-sample.94740/#post-524624

 

I really like the Mac 4 into 1 on my maxim 750

 

Thanks specialk! Really does look sharp on the 550! Sounds great too.

Thanks to all for the input. I think I'm getting the jist of it. Everybody seems to have done some re-jetting, which is fine, as I'm going to tear down the whole bike and will be giving it all the proper treatments. I'm just trying to line up all of my major parts, so I can fit everything before tear-down, in case I want/need to modify or fabricate parts or mounts. I'll be removing much of the excess, so I want everything to jive.

 

My understanding (and this is only my understanding, not a fact) is that the Marving system is an exact copy of the original Yamaha system and should not need rejeting. I think the same is true (in a functional sense) of the MAC 4-2. You may want to contact the manufacturers before you buy to see if either of them can confirm whether you will need to rejet or not.
I have not used either system and can only rely on what I've read on various forums.

 

Thank k-moe. I'm still debating pods, which will make changing the exhaust a moot point as far as jetting is concerned. I'm waiting to see if I can track down Rick Massey, so he can talk me out of it, then I can stick with the 4-2 and no re-jetting. We'll see...

 

Rick isn't around much anymore (like twice in the last year).
I'll talk you out of pods though.
See that link in my signature? Have a read.

 

I've been reading it. Too funny. I get it. It's just purely aesthetics for the project. Gotta figure something out. I noticed Rick wasn't on here anymore. Was hoping I could track him down the old fashioned way. I'm in his neck of the woods often.

 

i farted around for almost a year getting a stock air filter frame wrapped with two layers of Uni foam to run right. Didn't happen until i went to a Supertrapp muffler on a Mac 4-1 so i could change the back pressure

 

If you want a marving system you should have a look at Ebay.it, i saw some there pretty cheap a while ago.