Topic: Exhaust Question

[walkingchaos]

Ok so i found an exhaust I want for my bike project but im not sure if it will work. My bike is a 73 CB750, it has the exhaust flanges that are mounted to the engine and then the pipes clamp on with finned clamps. The exhaust I have found from another member here is from a 76 and it has the type of exhaust flanges that seem to fit into the engine and then has plates that screw down. My question is will that exhaust work on my 73 motor ? Can i remove the small pipes that come out of my motor and just install the exhaust from the 76 ? Thanks for any advise guys.

[voxonda]

Yes, it (sometimes) is possible to remove the original flanges, but they can be a pain............to remove.

Good luck.

[walkingchaos]

so its tough to get the exhaust flanges out ?

[voxonda]

Not always, but more then often the bolts are corroded in the aluminium of the head. It helps to heat the head, carefully, round the area where the bolts sit. The aluminium will expand more then the bolts, so hopefully, they all come out. Use a impact screwdriver, with a new bit.

Good luck.

Rob

[walkingchaos]

will a standard butane torch (like youd use for plumbing) work to heat the fittings ?

[HondaMan]

will a standard butane torch (like youd use for plumbing) work to heat the fittings ?

Yep. Propane, too. The hotter "plumbing" torch fuels can even melt the aluminum, so be a little careful there...the finned clamps run about 325 degrees, the engine fins behind it run about 300 degrees, when the engine is warmed up, use that rule of thumb.

The later ones use two halves of a crescent-moon shaped insert, held in by the finned clamp, to press the pipe against the copper gasket in the head. When you remove the existing "collar clamp", you will see a flattened copper ring buried in the carbon, against the port. Replace this, or your new pipes will leak right there. The new pipes press against this ring, the half-moon clamps press it to the head, and the "flower" provides the leverage when you tighten its screws (some have studs and nuts).

[walkingchaos]

do you guys use air powered impavt wrenches or electric when need be ?

[GammaFlat]

The type that you hit with a hammer (I call hammers "persuaders").  You apply counter clock-wise rotational pressure into your phillips screw head with an appropriately sized bit and blammo.  Make sure you have your impact driver "heading in the right direction".  I have been a big fan of these at times but have moved away from them a "bit".  I really like using a #3 bit on the engine sidecover screws with my trusty snap-on ratcheting screwdriver.  The correct bit makes a lot of difference. 

In terms of the screws that go into the head around the exhaust port, make sure you have an appropriately sized bit (absolutely critical for phillips - if it fits, it ain't too big and you should try larger) and you should be good to go without all the "impact".  Mine (which I'm about to remove) are "socket head" or allen on a set of MAC 4-1.  I'll post here if it doesn't go well .  I will be using copious amounts of "anti-seize" fluids.  In my case, I'll be using 50% trans fluid and 50% acetone. 

[walkingchaos]

ya i was planning on using alot of "nut buster" before attempting to remove the screws from the head.  have plenty of different sized screw drivers and screw bits for both my socket wrench and an impact driver (if i get one) Other then an impact driver would you guys suggest trying a large screw driver or a socket wrench with a bit first ?

[mgmuellner]

ya i was planning on using alot of "nut buster" before attempting to remove the screws from the head.  have plenty of different sized screw drivers and screw bits for both my socket wrench and an impact driver (if i get one) Other then an impact driver would you guys suggest trying a large screw driver or a socket wrench with a bit first ?

Start with the correct tool.  If you mess with it with the wrong tool, you're just making matters more difficult.  An impact driver isnt expensive or hard to find, but will save you many a beer - headache & curse word.

[walkingchaos]

hehe ok, I have an 18volt Ryobi tool set and they have an impact driver that Ill try first.