Topic: 750F Exhaust help!!! Urgent!!

[GroovieGhoulie]

Wanting to get the bike back together for a big ride tomorrow and the exhaust is vexing me.

The muffler is in excellent shape, but the header pipes are blued at the first bend.  I found and bought an excellent condition header and am going to replace it so the bike looks better.  I checked the exhaust valve clearances and cleaned the carbs, so they shouldn't re-color.

Problem is the muffler is held to the header with a 12mm bolt and a bolt with a totally round head!!!!  WTF??  How did Honda put these on and then get them off to fix things?  The round bolt has the factory yellow paint on it, so it wasn't rounded previously, it IS a ROUND head bolt.

What tools can remove/install it, or do I need special tools?

Thanks in advance.

[MrFry]

is there a nut on the back?

[GroovieGhoulie]

is there a nut on the back?

The nut is part of the clamp that holds the muffler to the header.  It's welded on there.  This is a WEIRD design!

[mick750F]

   I think that should be a flange bolt on there. It's not a hex bolt that someone rounded off? If it's that or a true round head bolt can you cut a slot in it to get a screwdriver on it? That's all I got...

Mike

[GroovieGhoulie]

Pics.  Not so good (Camera phone), but maybe y'all can get the idea.

[BobbyR]

Pics.  Not so good (Camera phone), but maybe y'all can get the idea.

If there is a nut on the back end, you can grind/file some flats on the round whatever that is and turn it off with a wrench.

[MrZxp]

Yes, mine has the round headed bolt also. I just figured some PO had thrown it on there at some stage when they had the muffler off! Anyhow, the venerable vice grips were utilised and that sucker came off in no time...

If I remember correctly, I couldn't find a correct size replacement in my collection of bolts at the time, so it went back on the same way it came off... 

A mystery to me as to why such a bolt should be employed... perhaps some other learned F owner will chime in with an explanation?? 

Cheers, Phil

[GroovieGhoulie]

Well it looks like it's gonna rain like a mofo tomorrow, so it can wait another day.

I was hoping to have it all together tonight as well.  Just finished putting new tires on her, so I wanted to have her perfect.

[meb1948]

I have one of those round nuts on my 1976 400F.  I replaced the entire exhaust last year and used
a pair of needle nose vice grips to remove the round nut.  The bolt which secures the clamp is
installed from the bottom and I think this round nut prevents the bolt from backing out and falling
on the ground.
When I got everything back together I reinstalled the round nut with the same pair of vice grips.

Mark.

[rhinoracer]

Could there be a phillips slot covered by rust? I completely disassembled the bike with a phillips screwdriver and a 10mm socket.