EXHAUSTed!

[Honzilla]

Someone PLEASE help me...

I blew it and gave up a chance to buy a nice second hand set of stock exhaust for my 1991 CB 750 Nighthawk...

So I really need help.  Where I live it is IMPOSSIBLE to find used parts this old, and a new set will cost me around $1200!!!

I love my bike and I am afraid that the leaky exhaust and popping is going to harm my newly rebuilt motor.  

[katman]

I ran into the same thing on my 75. 1200 to 1500 for new ones. Used ones weren't that much better than what I have. I had to go with a Mac 4 into one.

[Re-run]

What part of your pipes is bad? Do the header pipes themselves have holes? If they leak at the engine, a new set of gaskets is all you need there.
If the mufflers have holes, then you could probably hack off the muffler and get a set of slip-ons.
As slip-ons are universal usually, you sometimes have to get a small bit creative with mounting but it is generally not too difficult.
This is a unit on ebay right now. Not in too bad of shape.
http://www.ebay.com/itm/1991-Honda-Nighthawk-CB750-4-1-Exhaust-w-Vance-Hines-Pipe-Nice-/190600688081?pt=Motorcycles_Parts_Accessories&hash=item2c60afb1d1&vxp=mtr

Here is a vance and hines if you have a 4-1, this would slip on.
http://www.ebay.com/itm/1993-NIGHTHAWK-CB750-750-VANCE-HINES-EXHAUST-MUFFLER-/170690440733?pt=Motorcycles_Parts_Accessories&hash=item27bdf16e1d&vxp=mtr

 new vance and hines is about 323 here =
http://www.motorcycle-superstore.com/1/5/88/9981/16761/PITEM/Vance---Hines-4-into-1-Street-Megaphone-Exhaust-System-1991-Honda-Nighthawk-750-Parts.aspx
A stock system seems to be available but about $750 or so on cheapcycleparts.com

[Honzilla]

Did you have to get a jet-kit for your carbs?

Are you still using your OEM air box?

[Honzilla]

Whether I were to go with the Mac system or the Vance & Hines, can I keep my OEM center-stand?

Will I need a jet-kit for my carbs?  Can I use the OEM air box?

[Re-run]

You can but you would need to make a stop for it. The left side pipe, at least on my 78, has the rubber stop for the centerstand. I am sure something could be fabbed up fairly easy, just dont fab it to the swingarm!

Oh, and if it is just an exhaust change, most likely a jet change won't be needed if you keep the stock box and filter. Even if you do change to a K&N filter in the stock box, you should be ok with just a little twiddling on the idle mix screws and MAYBE a step up on mains.

[Honzilla]

I did a careful inspection.  This things is holier than swiss cheese.  4 holes I can see 2 or 3 i can feel...

Looks like the only alternative is full replacement.

Found a 4-1 system by Mac, that I can get here in Hong Kong.  Little pricy, but WAY cheaper than OEM.

[TOOLS1]

The black one would look cool on your bike. I have never heard anything bad about the Mac systems. My buddy has one on his bike, and likes it.
TOOLS