Any tricks to getting stuck exhaust mounting screws on the two center cylinders out?

[Buck]

I had to use an impact screwdriver to get the screws loose on the two outside cylinders. The issue is that I can't get the finned "collar" far enough out of the way to get at the screws with anything other than a normal screwdriver. They hit the frame before they slide far enough down the pipe to make clearance for the impact driver.

Any ideas or other methods for getting the stuck screws out?

 

[amc49]

my bad...............................................

 

[madmtnmotors]

I had to use an impact screwdriver to get the screws loose on the two outside cylinders. The issue is that I can't get the finned "collar" far enough out of the way to get at the screws with anything other than a normal screwdriver. They hit the frame before they slide far enough down the pipe to make clearance for the impact driver.

Any ideas or other methods for getting the stuck screws out?

If the clamping collars are loose, then it sounds like you are dealing with the spigot type of exhaust (typically CB750 1976 and earlier). Once the finned clamping collars are loose there is no need to remove the spigots (that remain bolted to the head). With the finned clamps loose simply remove the exhaust. The pipes slip over the spigots and the finned clamps hold the pipes to the spigots.

EZPZ

 

[Buck]

@madmtnmotors thanks, It is a 74, it's got an RC exhaust on it if that makes a difference.

The spigots don't look like they are parallel to each other so I figured I needed to unbolt the entire thing from the head because of that. I had the collars loose and hosed the @#$@# out of it with PB Blaster and couldn't get the exhaust to budge. At least the two outside ones are loose now, I'll give it another spray with the PB Blaster and see if I can coax it off with a rubber mallet.

 

[amc49]

Spigots may NOT be parallel, header may have slight pipe irregularities in the end shape and have collapsed the seals in varying amount to be slightly different in position. I'd be careful with that, trying to get dead straight could crack a valuable pipe. Let the header tubes go where they will, not nearly all of them run exactly the same. There are slight differences in absolute points in space on every header out there.

It'll be your judgement on that of course, just some thoughts.

 

[Buck]

Thanks for the input, I was able to get the exhaust off tonight after a few failed attempts. I managed to pry, tap and twist one of the collars by the frame. So with only one left to deal with I ended up getting tired of messing around and just went caveman on it. I used 2 vice grips and just pried it open and over the exhaust.

After all of that I found out the muffler part of the exhaust is rusted almost thru on the bottom side... oh well.

 

[amc49]

If the front header pipe still good pipe has some value still. But that kind of corrosion screams look close inside the pipe join area at the collector, they commonly rust at the center 'x' welded in to seal the middle between all pipes.

 

[Buck]

Yeah, the header is in pretty bad shape too.... looks like it may have been damaged at one point. It has a new tube welded into part of it. That's why I had trouble getting the collar over it.

 

[amc49]

Pretty extreme method but I have an old Kerker original for DOHC that I really liked but it got crunched once going over a curb to knock in the lower two pipes pretty bad. It also leaked right in the middle of the 'X' filler piece in the middle of the 4 tubes at collector. I brazed that hole shut and found plugs to TIGHTLY fit the collector opening and the 4 tubes and then strapped around them with worm drive hose clamps like used on car radiator hoses. All so I could make a fixture in one plug to air the pipe up with compressed air, at around 100 psi or so (EXTREMELY DANGEROUS!!!!) and heat the dents red hot with a torch they pulled out so perfectly you cannot tell where the damage was at all. I did the work outside as a safety thing and nobody else around while I did it and the plugs pointed up at the sky, one time one not tight and it went literally into space, so small I couldn't follow where it went.

 

[Buck]

That's some funny stuff! I can picture it... Mine looks like it may have had a run in with a curb as well. It's got a nice flat spot on it right where the 4 pipes merge together. Between that, all of the rust and the poorly replaced pipe I figured it's headed for the dumpster as soon as I get tired of tripping over it in the garage.