Those running exhaust without the 'balance tube'...

I've sourced a great condition full system for my 82 650, with the exception that some ham fisted PO has mangled and cut off one side of the balancing tube that joins the two halves of the system together.

I've sourced a flexible exhaust joining section which I plan to have welded onto the damaged section, and mate with the good side. However, my local welder seems to be getting his knickers in a twist over how to align the sections and keeps calling me to see if I'm available to help out(?!)

I'm losing faith in his services and am tempted to pull out altogether. But I suppose another option is to simply have him cut the balance tube off completely and weld the opening(s) shut - thus creating two distinct halves of the exhaust system.
I wanted to retain a stock system as much as possible but parts are so hard to come by for Maxims in the UK.
My question is how many of you guys are running 4:2:1, 4:1, 4:2 systems without any balancing sections and have you noticed any ill effect to the running of your bike at all?

 

I have a 4 into 1 on my 550 and it without a doubt makes more power than the stock exhaust I had on it before. That's not really a fair comparison though for your situation. I had a Suzuki gs650 with a rusted out exhaust equalizer, I just cut it out and welded the holes like you mentioned and the bike still went like stink, sounded alot better too.

 

Interesting.
I didn't pay too much for the system, it's tempting just to suck it and see how it goes with the equaliser removed/welded closed.
If anyone thinks this is definitely not a good idea please let me know

 

there is a thread on exhaust systems and it explains why the reason for the collector box and connector pipe.

I think is was chacal who responded to a question like yours
.
just dont remember the title

 

Im guessing you may mean this one?: http://www.xjbikes.com/forums/threads/4-1-exhaust-vs-4-2.91045/#post-516263

Which would point the finger at uneven back pressure should the 'crossover pipe' be eliminated. Would be keen to here from others that have run their system like this.

 

what if no one runs their system without the crossover pipe??

for oem exhaust if you cut the pipe and weld closed..think this way Yamaha would not have put it there if it were not needed.

find a different welder

from the link
"If cylinders #1 and 2 --- which fire sequentially (and, thus need to exhaust their spent gases sequentially) ---- were to share the same exhaust cavity, then their (sequential) exhaust gas flows would be "spaced" too close to each other (in time) and would see vastly different back-pressures (cylinder 2, which fires after cylinder 1, would see more back-pressure than cylinder 1, which emptied itself into a, well, into an "empty" exhaust collector)."

The same thought goes for the other two cylinders (# 2 and 3). Notice how even the aftermarket "dual" exhaust systems suffer from the above problem, since they are really two separate system, one system being for cylinders #1 and 2 (left side) and the other being for #3 and 4. Notice how it's the "sequential" problem.....since cylinders 1 and 2 fire (and exhaust themselves) sequentially, and since those gases vent into one common chamber, that cylinder #2 is going to see more backpressure than cylinder #1 will......and same for #3 and 4.

This un-balanced situation....with different cylinders seeing different exhaust system back-pressures......can (and does) result in different amounts of burnt gas scavenging from the differing cylinders, which is not the way to get an engine to make the most amount of power."

 

There are people here who DO have 4/2 but no crossover. I have had a couple systems like that, too.......the only thing that I really notice is that they feel like they run a bit smoother with the crossover pipe.

 

Yeah I wondered if there could be a distinguishable 'smoothness' difference. I guess I was hoping a couple of 4:2 owners would come along and say that they have categorically noticed zero difference without the crossover pipe.

 

if the pipe were not needed yamaha would not have put it there.
so if you can live with the bike running a bit rougher seal them off ,of course it will always be at the back of your mind when troubleshooting the bike.

 

I hear you. Sometimes there is an element of over engineering built into these things though.
Having said that, I've had a promising conversation with a local custom bike fabricator today who seemed to speak my language - fingers crossed for a better outcome.

 

The only XJ that I've seen with a 4-2 factory exhaust (and no balancer pipe or box) was the XJ600 (Seca II). It had the 1/4 and 2/3 cylinders tied. Makes sense if you remember that the firing order is 1, 3, 4, 2.

 

So I just handed by exhaust over to this guy for repair: http://www.rbkustoms.com/

Expecting good things.

 

It was worth the wait!
Russ did a really impressive job fabricating a stainless tube to fit perfectly and the welds are really neat. It now looks better than new! Price was also very reasonable, I'm so happy that I shopped around and found this guy.
Also got to chat with him today about some of his custom bikes and have a close up look at some of his work, what a treat.
He's happy to take on small work and his pricing often works out cheaper than sourcing parts elsewhere and customising them to fit (forward controls etc).