4 to 1 exhaust

I'm sure this has been on here many times, but on my 82 xj750 there are a few exhaust leaks on the original pipes. Considering a 4 to 1 build. I know by changing the exhaust my carbs won't like it without modifying. Anyone have any tips on how to go about this?

 

From what i read and my own personal experience you shouldnt have any trouble. Your exhaust can move more air than your intake can bring in. I pit a 4into1 on my xj750 and had no issue. Now someone smarter than me my have something different to say.

 

I made my own 4-1 by using XJ750 headpipes into a XJ650 Turbo collector. The Turbo collector bolts to the underside of the motor just like the stock exhaust. Find a silencer on e-bay then fabricate an S-pipe to bolt to the turbo collector and slip into the silencer.
Its been a bunch of years since I did this and I recall cutting off a centre stand lug which was in the way, I can't recall this part clearly. I'm not suggesting you eliminate the centre stand as it's definitely useful for tire changes and just general tuning. I have a Turbo now also so I can see what is different with it.
If you're interested I can take some pics underneath there to see if any cutting can be avoided.

 

That was going to be the route I went for a 4-1 originally. So if you need a turbo manifold collector, I have one. haa

 

Was also maybe thinking about getting of of the airbox and going for a pod look, but I know how much cv carbs hate pods and not sure if it's worth doing. Anybody have pods?

 

I do and i hate them. But if you do go that way i would be interested in your airbox

 

To my understanding, there needs to be a velocity stack for the CV to work properly. So If you put together a compact bread box with velocity stacks inside, you should be able to have your cake and eat it too. I'm currently in the process of building one. I'll let you know how it goes.

 

Yes pics would be nice

 

I made up a 4 into 1 after dealing with hitting too many speed bumps with a standard 4 into 1 setup.
With a bit of time up your sleeve, a bender, welder and other bits... this may be helpful. Works like a charm so far.
http://www.xjbikes.com/forums/threads/my-exhaust-creation.106337/

 

That should be enough of a review of pods to convince anyone...

 

I was going to ask a similar question myself, since my stock megaphones have rust holes in them. I was considering going to a 4 into 1 setup but I would prefer not to rejet. I have a non YICS engine, running stock airbox if that matters. Has anyone had experience with the MAC 4 into 1 systems for the 650 maxim? If so, were carb adjustments necessary?

 

Last summer did some tuning on an xj650rjc with a mac 4-1. Keep in mind a Canadian model starts out with larger main jets(112) I went +1 size on pilot and main with a K&N air filter and the bike ran very well. No flat spots in power delivery. And in 4th and 5th gear pulled hard all the way to 9000+rpm.

My own xj650rjc is bone stock but for the K&N filter and the bike with the 4-1 did respond slightly quicker, not enough that I would ditch my oem exhaust